Glossar zur Zellkultur

BAE-1

The BAE-1 cell line is derived from the aorta of a Friesian cow. BAE-1 cells form "sprouts" after reaching confluence and secrete proteoglycans and collagen. The cell line is infected with Bovine Viral Diarrhea Virus (BVDV), which is non-hazardous to humans and very common for ruminants.

BHK-21

The BHK-21 cell line is a fibroblast cell line that grows adherently. It was derived in 1961 by single-cell isolation from the kidney of five unsexed, 1-day-old hamsters. BHK cells are used to study viral infections. They are also useful for transformation, as well as stable and transient transfections.

Blastocyst

A structure of early mammalian embryogenesis, after formation of the morula.

BME

Basal Medium Eagle

Bone marrow

Bone marrow is a semi-solid tissue found within cancellous or spongy portions of the bone. In mammals and birds, it is the place where hematopoiesis takes place. Mesenchymal cells can be isolated from bone marrow tissue.

BSA

Bovine Serum Albumin

BSE

Bovine spongiform encephalopathy

BSS

Balanced Salt Solution

Budapest Treaty

A European-wide treaty/agreement of terms by which patents can be legally recognized under European law. This was put in place to combat the variation in patent regulations between so many countries in Europe. ECACC is a recognized depository for patents under the Budapest Treaty.

BUdr

Bromo-deoxy Uridine

BVDV

Bovine Viral Diarrhea Virus

Ca₂₊

Calcium ion

Cancer

Cancer is the uncontrolled development of cells. Usually, cells die and are replaced when they get too old or get damaged. Cancer begins when genetic changes interfere with this natural process. The cells may form a mass called a tumor, which can be malignant (spreading across the body) or benign (remaining locally). Some types of cancers do not form a tumor, such as leukemia, lymphoma and myeloma.

Cancer Stem Cells

Cancer stem cells (CSCs) are found within tumors or hematological cancers and show characteristics of normal stem cells, i.e. they may give rise to all cell types found in the cancer sample. In cell culture, these cells are often grown in a 3D tumorsphere culture.

Cardiomyocyte

A muscle cell type found in the heart that allows it to beat rhythmically and continuously.

CEA

Carcinoembryonic Antigen

Cell Culture

Maintenance or cultivation of cells in vitro in which the cells are no longer organized into tissues. Origin tissue is disassociated by cell migration or mechanical or enzymic means.

Cell Cycle

The series of activities that each cell goes through. There are 5 recognized phases of the cell cycle: G0 - rest phase, G1 - 1st gap phase where cells prepare to synthesize DNA and undergo mass synthesis, S - cells synthesize DNA and double 2n to 4n, G2 - 2nd gap phase where the cells prepare to divide and M - mitosis.

Cell Generation Time

The interval between consecutive divisions of a cell.

Cell Hybridization

The fusion of two or more dissimilar cells, leading to the formation of a synkaryon.

Cell Line

A cell line arises from a primary culture of the first successful sub-culture. The term cell line implies that cultures from it consist of lineages of cells originally present in the primary culture. The terms finite or continuous are used as prefixes if the status of the culture is known. If not, the term line will suffice. The term 'continuous line' replaces the term 'established line'. In any published description of a culture, one must make every attempt to publish the characterization or history of the culture. If such has already been published, a reference to the original publication must be made. In obtaining a culture from another laboratory, the proper designation of the culture, as originally named and described, must be maintained and any deviations in cultivation from the original must be reported in any publication.

Cell Phase

A description of the stage of growth that a cell population is in. There are 4 recognized phases: Lag Phase - where there is no net increase in cell number as the cells adapt to their environment, Log/Exponential Phase - where the population increases exponentially, Plateau - no net increase in cell numbers as the limits of space, nutrients and other factors are reached and Death/Decline Phase - where there is a net decrease in the population as the cells begin to die. Cell phases are pictorially represented as a growth curve.

Cell Strain

A cell strain is derived either from a primary culture or a cell line by the selection or cloning of cells having specific properties or markers.

Cell-based therapy

A medical therapy form in which cells are used to repair other damaged or destroyed cells.

Chemically Defined Medium

A nutritive solution for culturing cells in which each component is specifiable and, ideally, is of known chemical structure.

CHO

Chinese Hamster Ovary cells were derived from the ovaries of the Chinese hamster. Since the 1980s, CHO cells have started to rise as the gold standard for industrial production of recombinant protein therapeutics (e.g. large-scale production of antibodies). CHO cells grow rapidly in suspension culture and can be grown in serum-free media (animal-free, chemically defined). They show a high protein production and allow for post-translational modifications, making them ideal for human applications.

Chromosome

Within the nucleus of a cell, the DNA is packaged into condensed, thread-like structures called chromosomes. Each chromosome is made from the DNA strand coiled tightly around structurally supporting proteins called histones. Chromosomes are not visible under the microscope unless the cell is currently dividing.

Clonality

The extent to which one clone is similar to another.

Clone

A clone is a group of identical cells that share a common ancestry (they derive from the same parent cell).

Cloning

Cloning refers to the biotechnical processes of creating DNA copies (molecular cloning) or cells (cell cloning). It may also refer to creation of a "copy" of a whole organism.

CO₂

Carbon Dioxide

Colony Forming Efficiency

The percentage of cells plated (seeded, inoculated) that form a colony. Also known as plating efficiency.

Conditioned Medium

Medium containing growth factors secreted by other cells.

Confluency

The percentage to which adherent cells cover the substrate (e.g. Flask). Note that cells should regularly be subcultured at around 60-70% confluency, but please refer to the cell line data sheet or catalog information as some cell lines do not reach this level of confluency.

Contact Inhibition

The property of a cell to cease division when in contact with neighboring cells or when growing in restricted space

Continuous Cell Culture

A culture that is apparently capable of an unlimited number of population doubling; often referred to as an immortal cell culture. Such cells may or may not express the characteristics of in vitro neoplastic or malignant transformation. (See also 'immortalisation')

COS-7

The COS-7 cell line was established by transformation of CV-1 cells with an origin defective mutant of SV40. COS-7 cells grow adherent and are considered a fibroblast cell line. The main use of COS-7 cells is as a host for transfection. Due to transformation by SV40, it is also a good model for the study of this virus and its involvement in human cancers.

CPE

Cytopathic effect caused by viral infection of cell lines, causing the morphology to change.

Cross Contamination

When one cell culture has been introduced to another, giving rise to a mixed cell population. If one cell type grows more vigorously than the other, then that cell type will prevail.

Cryopreservation

Ultra-low temperature storage of cells, tissues, embryos or seeds. This storage is usually carried out in the vapor or liquid phase of nitrogen.

CS

Calf Serum

Culture medium

A culture medium supplies cells with nutrients and anything else they might need to grow in vitro. It may also lack defined compounds in order to promote selection of a certain phenotype.

Cytoplasm

The cytoplasm is a thick liquid that fills the cell and is enclosed by the cell membrane. It holds all organelles, except for the nucleus. It is mainly composed of water, salts, and proteins.

Differentiation

The defined process whereby individual cells characteristically change to a more specialized function.

Diploid

The state of the cell in which all chromosomes, except sex chromosomes, are two in number and are structurally identical with those of the species from which the culture was derived. Where there is a Commission Report available, the experimenter should adhere to the convention for reporting the karyotype of the donor. Commission Reports have been published for mouse, human and rat. In defining a diploid culture, one should present a graph depicting the chromosome number distribution leading to the modal number determination along with representative karyotypes.

DMEM

Dulbecco's Modified Eagle Medium with 4.5g/L Glucose

DMSO

Dimethyl Sulphoxide

DNA

DNA (deoxyribonucleic acid) is a nucleic acid that contains the genetic information used in the development and function of living organisms.

DNA methylation

DNA methylation is a chemical modification of DNA that can be inherited and subsequently removed without changing the original DNA sequence.

DXMT

Dexamethasone

EBNA

Epstein Barr Nuclear Antigen

EBV

Originally a Human lymphotropic herpes virus that is now used in the immortalisation of B lymphoblast cells

ECACC

European Collection of Authenticated Cell Cultures

Ectoderm

The ectoderm is one of the three germ layers in animal embryogenesis. It forms the nervous system, the ganglia and nerves, the epidermis, hair, and mammary glands, the lens of the eye, cranial and sensory, pigment cells,  and head connective tissues.

Ectopic Expression

Ectopic expression is the expression of a gene in an abnormal place within the organism. This may be caused by a disease, or it can be artificially initiated to help determine what the gene function is.

EDTA

Ethylene Diamine Tetra Acetic Acid

EGF

Epidermal Growth Factor

Embryo

An embryo is an early stage of development of a multicellular organism. It ranges from the first cell division until birth, hatching, or germination. In human development, the first 10 weeks are defined as an embryo.

Embryonic stem cells

Embryonic stem cells are pluripotent stem cells derived from the inner cell mass of the blastocyst.

EMEM [HBSS]

Eagles Minimum Essential Medium with Hanks Balanced Salt Solution

Endoderm

The endoderm is one of the germ layers formed during animal embryogenesis. The endoderm later forms: the stomach, liver, colon, pancreas, urinary bladder, the lining of the urethra, the epithelial parts of the trachea, the lungs, pharynx, thyroid, parathyroid, and the intestines.

Enucleated cell

A cell where the nucleus - and therefore all genetic information - has been removed.

Epigenetics

Epigenetics is the study of heritable phenotype changes that do not involve alterations in the underlying DNA sequence.

Epithelial-Like

Resembling or characterization of, having the form or appearance of epithelial cells. In order to define a cell as an epithelial cell, it must possess characteristics typical of epithelial cells. For example, often epithelial cells will appear cuboidal when viewed under the light microscope and grow in sheets wherein the cells are in quite close contact with one another. In some types of epithelial cells, the nuclear to cytoplasmic ratio will be relatively high when compared to fibroblast cells.

Expression

Expression is the process by which the information stored in a gene is used to produce proteins.

F10

Ham's F10 nutrient medium

F12

Ham's F12 nutrient medium

F12k

Modified Ham's F12 nutrient medium

FACS

Fluorescence-activated cell sorting (FACS) is a specialized type of flow cytometry. With FACS, heterogeneous mixtures of biological cells can be sorted into two or more containers, one cell at a time, based upon the specific light scattering and fluorescent characteristics of each cell.

FBS

Fetal Bovine Serum (also known as FCS)

FBS (Fetal Bovine Serum) / FCS (Fetal Calf Serum)

Serum from blood plasma that contains the wide range of nutrients necessary to support the growth of cells in culture.

FCS

Fetal Calf Serum (also known as FBS)

Feeder Layer

A layer of cells, usually lethally irradiated or chemically treated to stop DNA synthesis, upon which are cultured a fastidious cell type.

Fertilization

Fertilization is the fusion of gametes in order to produce a new organism.

Fetus

The fetus is the stage in mammalian development after the embryo and before birth. In humans, the fetal stage of prenatal development starts at the beginning of the 11th week in gestational age.

FGF

Fibroblast Growth Factor

Fibroblast

Fibroblasts are the most common cells of connective tissue in animals. A fibroblast synthesizes the extracellular matrix and collagen, produces the stroma and is essential for wound healing.

Fibroblast Like

Resembling or characteristic of, having the form or appearance of fibroblast cells. In order to define a cell as a fibroblast cell, it must possess characteristics typical of fibroblast cells. For example, often fibroblast cells will appear pointed, elongated or stellate when viewed under the light microscope and grow in sheets wherein the cells are rather loosely in contact with one another. The cells may produce parallel arrays at confluence. In some types of fibroblast cells, the nuclear to cytoplasmic ratio will be relatively low when compared to epithelial cells.

Finite Cell Lines

Cell cultures that will only survive a certain number of population doublings before senescence. All normal cells are finite.

Gag

Gag is a lentiviral packaging element that encodes for a structural precursor protein.

Gamete

A gamete is a cell that fuses with another cell during fertilization (conception).

Gastrulation

Gastrulation is the phase in early embryonic development of animals, during which the single-layered blastula is reorganized into a multilayered structure known as the gastrula.

Gene

A gene is a DNA or RNA sequence that encodes for a gene product, which can be either RNA or protein. During gene expression, the DNA is first copied to RNA. The RNA can directly function or act as an intermediate template for a protein.

Gene silencing

Gene silencing is the interference with a specific gene that inhibits its expression.

Genetic Drift

A change or mutation in the genetic makeup of a cellular population induced by long term culture or a change in growth conditions.

Genomics

The systematic study of genes and their function.

Germ layers

The germ layers are the primary layers of cells that are formed during embryonic development. They consist of the endoderm (inner layer), the mesoderm (middle layer), and the ectoderm (outer layer). As the embryo develops, these layers interact with each other and lead to the formation of all organs and tissues.

GM-CSF

Granulocyte Macrophage Colony Stimulating Factor

GMEM

Glasgow's Modified Minimum Essential Medium

Growth Curve

See Cell Phase.

Growth Factors

Usually proteins required by cells for their growth and metabolism. Most cell lines are satisfied by those growth factors included in serum, but others require additional supplements.

HAT

Hypoxanthine, Aminopterin, Thymidine Selection medium used in production of hybridomas.

HB

Hybridoma Supplement

HCG

Human Chorionic Gonadotropin

HEK-293

Human embryonic kidney cells (HEK or HEK-293) are one of the most commonly used cell lines, following the HeLa cell line. HEK cells are derived from human embryonic kidney cells that were grown in tissue culture. HEK cells are considered reliable in growth, robustness and ease of transfection and have therefore been used in cell biology for many years. HEK cells are used industrially to produce therapeutic proteins and viruses for gene therapy, in research HEK cells are often used as hosts for gene expression.

HeLa

The HeLa cell line is the most commonly used human cell line and also the first cell line to be cultivated in a laboratory. It originates from cervical cancer cells of Henriette Lacks, who died of her disease one year after the diagnosis. HeLa cells are immortal, remarkably durable and highly prolific. HeLa cells share various similarities with normal cells, despite being a cancer cell line, and can therefore be used to study basic human cellular functions.

HepG2

HepG2 is a hepatoma cell line which can be used as an alternative to primary human hepatocytes. HepG2 cells are non-tumorigenic, epithelial-like and highly prolific liver carcinoma cells. HepG2 can - just like hepatocytes - differentiate and form apical and basolateral cell surfaces. Therefore, HepG2 can be used to study the intercellular transport of molecules between different cell types. HepG2 is most commonly used for research on liver metabolism, drug metabolism, and hepatotoxicity studies. The cell line can be grown at a large scale, stimulated by human growth hormone (hGH).

Hematopoiesis

Hematopoiesis is the formation of blood cell components during, which are derived from hematopoietic stem cells.

Hematopoietic stem cells

Hematopoietic stem cells (HSCs) are multipotent stem cells that give rise to two lineages: the lymphoid (T-cells, B-cells, and NK-cells) and myeloid lineage (monocytes and macrophages, neutrophils, basophils, eosinophils, erythrocytes, megakaryocytes/platelets, dendritic cells)

HEPA

High Efficiency Particulate Air

Hepatocyte

Hepatocytes are the main cell type found in liver tissue. They make up around 80% of the liver's total cytoplasmic mass.

Heterokaryon

A cell possessing two or more genetically different nuclei in a common cytoplasm, usually derived as a result of cell-to-cell fusion.

Heterologous

A heterologous (not homologous) cell population is a mixed or divergent cell population or derives of divergent origin.

Heteroploid

The term given to a cell culture when the cells comprising the culture possess nuclei containing chromosome numbers other than the diploid number. This is a term used only to describe a culture and is not used to describe individual cells. Thus, a heteroploid culture would be one that contains aneuploid cells.

Histocompatibility

Histocompatibility is the property of having (nearly) the same allelles of the major histocompatibility complex genes.

Histones

Histones are the main proteins contained in chromatin. The DNA is wound around the histones, which control access of the cell machinery and therefore gene regulation.

HL60

HL60 is a human leukemia cell line derived from a 36-year-old woman with acute promyelocytic leukemia. HL60 cells proliferate continuously in suspension culture with neutrophilic promyelocytic morphology. The cell line is mainly used for research on blood cell formation and physiology. HL60 requires transferrin and insulin to grow, and the cells can be differentiated to mature granulocytes by induction with DMSO or retinoic acid.

Homokaryon

A cell possessing two or more genetically identical nuclei in a common cytoplasm, derived as a result of cell-to-cell fusion.

Homologous Recombination

Homologous recombination occurs, when nucleotide sequences between two similar or identical DNA molecules are exchanged.

HS

Horse Serum

HT

Hypoxanthine, Thymidine

Human embryonic stem cells

Human embryonic stem cells (hESCs) are pluripotent stem cells which are derived from the inner cell mass of the blastocyst.

Hybrid Cell

The term used to describe the mononucleate cell that results from the fusion of two different cells, leading to the formation of a synkaryon.

Hybridoma

The cell, which results from the fusion of an antibody producing tumor cell (myeloma) and an antigenically-stimulated normal plasma cell. Such cells are constructed because they produce a single antibody directed against the antigen epitope that stimulated the plasma cell. This antibody is referred to as a monoclonal antibody

IBMX

3-isobutyl-1-methylxanthine

ICLAC

International Cell Line Authentication Committee

IDA

International Depository Authorities

IDMEM

Iscoves Modified Dulbecco's Medium

IL

Interleukin

Immortalisation

The attainment by a finite cell culture, whether by perturbation or intrinsically, of the attributes of a continuous cell line. An immortalized cell is not necessarily one, which is neoplastically or malignantly transformed.

In vitro

In vitro means that the conducted experiment merely tries to resemble the environment of the organism, yet the used components are isolated from the original organism and their natural biological context. This is done for a more detailed or more convenient analysis.

In vitro fertilization

In vitro fertilization (IVF) is the process by which the egg cell is fertilized by sperm outside the body.

In Vitro Neoplastic Transformation

The acquisition, by cultured cells, of the property to form neoplasms, benign or malignant, when inoculated into animals.   Many transformed cell populations, which arise in vitro intrinsically or through deliberate manipulation by the investigator, produce only benign tumors, that is, tumors which show no local invasion or metastasis following animal inoculation.

In Vitro Senescence

In vertebrate cell culture, the property attributable to finite cell cultures, namely their inability to grow beyond a finite number of population doubling, e.g. MRC-5, WI38 cells. Neither invertebrate nor plant cell cultures exhibit this property.

In Vitro Transformation

A heritable change, occurring in cells in culture, either intrinsically or from treatment with chemical carcinogens, oncogenic viruses, irradiation, transfection with oncogenes, etc. and leading to the acquisition of altered morphological, antigenic, neoplastic, proliferative, or other properties.

In vivo

In vivo experiments are conducted within the whole, living organism in their normal and intact state.

Induced pluripotent stem cells

Induced pluripotent stem cells (iPSCs) are reprogrammed adult stem cells. They are modified to an embryonic stem cell-like state by expression of certain factors which are responsible for embryonic stem cell properties.

Inner cell mass

The inner cell mass (ICM), also known as embryoblast, is the cluster of cells in the blastocyst stage of early mammalian embryogenesis.

Jurkat

The Jurkat cell line was derived from human T lymphocytes and originally obtained from the peripheral blood of a 14-year-old boy with T-cell leukemia. Jurkat cells are immortalized and have been mostly used to study T-cell signaling, T-cell leukemia, and molecular events of HIV infection. They are also used to investigate viral interactions, protein expression, and cancer biochemistry. Jurkat cells are able to produce interleukin 2 (IL-2), a signaling molecule of the immune system.

Klf4

KLF4 is a member of the zinc finger-containing Krüppel-like factor family. It regulates diverse physiological functions and cellular processes, such as somatic cell reprogramming, and also plays important roles in the pathogenesis of diseases including cancer and vascular diseases.

Knock-down

Gene knock-down is a method by which the expression of one or more genes of a cell/organism is (drastically) reduced via RNA interference (RNAi) or competitive inhibition.

L-15

Leibovitz's L-15

L929

L929 is an adriamycin-resistant cell line derived from a parent L929 murine fibroblast cell line that has been exposed to increasing concentrations of doxorubicin. The parent cell line was derived from normal subcutaneous areolar adipose tissue. L929 cells are used for the development of novel anti-cancer treatments.

Lentivirus

The lentivrius is a genus of retroviruses characterized by long incubation periods in mammalian species that cause chronic and deadly diseases. The best known lentivirus is the HIV, which causes AIDS. As they can deliver a significant amount of genetic information into the DNA of the host cell, lentiviruses are one of the most efficient vectors for gene delivery.

LH

Luteinizing Hormone or Lactalbumin Hydrolysate

LS

Lamb Serum

M199

Medium 199

MCB

Master Cell Bank

M-CSF

Macrophage Colony Stimulating Factor

Meiosis

Meiosis is a special type of cell division used by sexually-reproducing organisms. It produces the gametes, such as the egg cell and sperm cell. It takes place in two rounds of division that produces four cells with only one copy of each chromosome.

MEM

Eagle's Minimum Essential Medium

MEM (EBSS)

Eagle's Minimum Essential Medium with Earle's Balanced Salt Solution

MEM (HBSS)

Eagle's Minimum Essential Medium with Hank's Balanced Salt Solution

Mesenchymal stem cells

Mesenchymal stem cells (MSCs) are multipotent stem cells that can differentiate into numerous other cell types, such as: adipocytes, osteoblasts, and chondrocytes.

Mesoderm

The mesoderm is on the germ layers formed during animal embryogenesis. It later forms the skeletal muscle, skeleton, dermis of skin, connective tissue, urogenital system, heart, blood (lymph cells), and spleen.

Mg₂₊

Magnesium ion

Microbial Contamination

When a microorganism (adventitious agent) is introduced to a cell culture. Includes bacteria, yeast, fungi and mycoplasma. Most contaminants will disrupt the growth or growth conditions of a culture.

MIGB

M-iodobenzylguanadine

Mitosis

Mitosis is a part of the cell cycle, in which replicated chromosomes are separated into two new nuclei. The cell division gives rise to two genetically identical cells with the same chromosome count.

Monoclonal Antibody

An antibody secreted by a hybridoma.

Morphology

It is the study of the form and structure of a cell or organism and their specific structural features.

Multiplicity of Infection

Multiplicity of Infection (MOI) refers to the average number of viral particles within a single cell. It is calculated by dividing the total number of transducing units by the number of plated cells.

Multipotent

Multipotency is the ability to generate a progeny of several distinct cell types.

Myc (c-Myc)

Myc or c-Myc is an oncogene that codes for a protein that binds to the DNA of other genes. When this gene is mutated or overexpressed, it does not function properly and often is the cause of cancer.

MRC-5

The MRC-5 (Medical Research Council cell strain 5) is a non-cancerous diploid human cell line with the karyotype 46,XY. It was originally derived from the lung tissue of a 14-week-old aborted fetus. The cell line has a fibroblast-like morphology. The untransformed cell line can undergo 42-48 population doublings before senescence. The main use of MRC-5 lies in commercial vaccine production, as MRC-5 can be cultured in large volumes.

NaP

Sodium Pyruvate

NBCS

Newborn Calf Serum

NEAA

Non-Essential Amino Acids

Neural stem cell

Neural stem cells (NSCs) are multipotent stem cells that generate the main phenotypes of the nervous system. They have the ability to self-renew.

Neuron

A neuron is a nerve cell that carries electrical impulses and chemical signals. Neurons are the basic units of the nervous system. They have a cell body, an axon, and dendrites. Roughly 10% of all cells in the brain are neurons. Chemical signaling occurs via synapses, which are specialized connections with other cells.

NS0

The NS0 (NS: nonsecreting) cell line is a model cell line which was derived from murine myeloma. NS0 cells do not synthesize or secrete heavy or light chains of Ig. The cells grow in suspension, have a lymphoblast morphology, are cholesterol-dependent. Like all myeloma cells, they naturally produce antibodies. Many therapeutic antibodies are produced in NS0 cells, e.g. for MS or leukemia treatment. NS0 cells are phenotypically GS minus, and establishing a GS system for selection takes only 3 months.

Nucleus

The nucleus is a cell organelle found in eukaryotic cells. It is membrane-enclosed and carries most of the genetic information of the cell. The genome is organized as multiple long linear DNA strands, which are condensed into chromatin.

O₂

Oxygen

Osteoblast

Osteoblasts are a functional cell type responsible for creating bone mass.

Passage

The passaging of cells, also known as subculturing, is the process of disassociating, washing, and seeding cells into new culture vessels.

Passage Number

The number of times the cells in the culture have been subcultured or passed. In descriptions of this process, the ratio or dilution of the cells should be stated so that the relative cultural age gap can be ascertained. This term is not synonymous with population doubling.

PBS

Phosphate Buffered Saline(calcium and magnesium free)

PBS

Phosphate buffered saline

PHA

Phytohemagglutinin

Phenotype

The expressed characteristics of a cell or cell culture. This includes the morphology, markers, products secreted and all other physical attributes.

Plasmid

A plasmid is a small, extrachromosomal DNA molecule that is physically separated from chromosomal DNA and can be replicated independently. Plasmids are usually circular and double-stranded. They are most commonly found in bacteria, yet also sometimes found in eukaryotic and archaic organisms.

Plasticity

Plasticity is the ability of a cell or organism to change its phenotype in response to changes in the environment.

Ploidy

A description of the number of chromosome sets included in a cell. e.g. 2n - diploid/normal cells, 3n - triploid, 4n - tetraploid, etc.

Pluripotent stem cells

Pluripotent stem cells are stem cells that can self-renew indefinitely and give rise to any fetal or adult cell type.

PMA

Phorbol Myristate Acetate

Pol

Pol is a lentivral packaging element that encodes for a structural precursor protein.

Population Doubling Level

The total number of population doublings of a cell line or strain since its initiation in vitro. A formula to use for the calculation of 'population doublings' in a single passage is: number of population doublings = Log10(N/N0) X 3.33 where: N= number of cells in the growth vessel at the end of a period of growth N0= number of cells plated in the growth vessel. It is best to use the number of viable cells or number of attached cells for this determination. Population doublings level is synonymous with 'cell generation time'.

PPE

Personal Protective Equipment

Price Code

The way in which ECACC prioritizes its cell line stocks. Price code A reflects those cell lines ordered most often, and so the banks are larger and more cryogenic storage space is assigned to them. Other price codes consist of cell lines that are ordered less often and so stocks are smaller and more labor-intensive.

Primary Culture

A culture started from cells, tissues or organs taken directly from organisms. A primary culture may be regarded as such until it is successfully subcultured for the first time,  when it becomes a 'cell line'.

Pro-cck

Pro-cholecystokinin

Progenitor cell

Progenitor cells are able to self-renew but, unlike pluripotent stem cells, only have limited differentiation potential.

Proliferation

Refers to an increase in viable cell numbers in a population or when a single cell doubles.

Proliferation rate

The proliferation rate is defined as the time in between cell division.

PS

Propagating strain for staphylococcal bacteriophages

Pseudodiploid

This describes the condition where the number of chromosomes in a cell is diploid but, as a result of chromosomal rearrangements, the karyotype is abnormal, and linkage relationships may be disrupted.

RA

Retinoic Acid

RCD (Research Council Deposit)

Some cell lines in the General and Hybridoma collections at ECACC were deposited by the Research Council or with the aid of a Research Council grant. UK non-profit-making organizations may receive a single ampule of each RCD cell line free of charge. Please note that carriage charges will still apply

Regulatory viral protein

Regulatory viral protein (Rev) is a lentiviral packaging element that binds to Rev Response Element (RRE) sequences. This allows the export of viral RNAs.

Reprogramming

Reprogramming refers to the process of transforming a more specialized cell in to a pluripotent stem cell. This is accomplished by altering the epigenetic modifications.

Resuscitation

Process of reviving cells from a frozen state.

Retrovirus

Retroviruses, belonging to the viral family Retroviridae, are enveloped viruses with an RNA genome that replicate via a DNA intermediate. They rely on the enzyme reverse transcriptase for the reverse transcription of their RNA into DNA. The DNA can be integrated into the host's genome via the integrase enzyme. Afterwards, the virus is replicated as part of the cell's genome.

RPMI

Roswell Park Memorial Institute. Often used as an abbreviation for RPMI 1640 nutrient medium.

Saturation Density

The maximum number of cells attainable per cm2 (monolayer culture) or per ml (suspension culture) under specific culture conditions.

SDM

Schneider's Drosophila Medium

Seeding Density

The number of cells either per cm2 (if an adherent cell line) or per ml (if a suspension cell line) that are resuspended in a fresh flask after subculture. The recommended seeding density suggested by ECACC reflects the limits of a cell line to survive a split (i.e. too low and there will not be a large enough population to successfully colonize the flask, too high and insufficient nutrients and space will be available for growth of any considerable length of time)

Self-renewal

Self-renewal is the ability of a cell to undergo numerous cycles of cell division without differentiating, i.e. maintaining the undifferentiated state.

Senescence

The point at which a cell or cell culture terminally ceases to grow.

Serum-Free Medium

Specialized medium that contains additional supplements and growth factors so that cells can grow in the absence of animal sera. It is still the case that only cells adapted to serum-free growth will prosper in serum-free media.

SH-SY5Y

The SH-SY5Y cell line is a subclone of the original cell line SK-N-SH that was isolated from a bone marrow biopsy taken from a four-year-old female with neuroblastoma. SH-SY5Y cells are used for studies of neuronal function and differentiation. SH-SY5Y cells are adrenergic but also express dopaminergic markers and have therefore been used to study Parkinson's disease, neurogenesis, and other brain cell characteristics.

SMEM

Spinners Modified Minimum Essential Medium

Somatic cell

A somatic cell is a cell that forms the body of a biological organism. In other words, it is any other cell than a gamete, germ cell, gametocyte or undifferentiated stem cell.

Somatic Cell Hybrid

The cell resulting from the fusion of animal cells derived from somatic cells that differ genetically.

Stem cell

A stem cell is a cell that is able to self-renew or give rise to a specialized cell type via differentiation.

Stem cell niche

The stem cell niche is the microenvironment within the organism in which stem cells are located. This region is responsible for the balance of self-renewal and differentiation.

Stromal cells

Stromal cells are connective tissue cells of an organ.

Subculture

The subculturing of cells, also known as passaging, is the process of disassociating, washing, and seeding cells into new culture vessels.

Surface markers

A surface marker is a specific marker found on the surface of a cell.

Suspension Cell Lines

Cells that do not require anchorage in order to grow.

Synkaryon

A hybrid cell that results from the fusion of the nuclei it carries.

TAT

TAT is a lentiviral packaging element required for the efficient elongation of nascent viral transcripts.

Telomere

A telomere is a region at the end of each chromosome. It consists of a repetitive sequence and protects the end of the chromosome from deteriorating or fusing with neighbored chromosomes.

Teratoma

A teratoma is an encapsuled tumor that holds tissue or organ components that resemble normal derivatives of the three germ layers.

TGF

Transforming Growth Factor

TGM

Thioglycollate medium

THP-1

The THP-1 cell line is a human monocytic cell line which was derived from an acute monocytic leukemia patient. THP-1 cells have a large, round, single-cell morphology, and they express Fc and C3b receptors, while lacking surface and cytoplasmic immunoglobulins. Its main use lies in leukemia testing in immunocytochemical analysis of protein-protein interactions. THP-1 is also used in immunohistochemistry.

Tissue Culture

Traditionally, the maintenance of fragments of tissue in vitro, but commonly is used as a generic term including tissue explant culture, organ culture and dispersed cell cultures, i.e. cell lines and cell strains.

Titer

The titer is the number of transducing units per milliliter.

Totipotency

Totipotency is the ability of a cell to divide and produce all the differentiation types available within the organism, including extraembryonic tissues.

tPA

Plasminogen Activator

TPB

Tryptose Phosphate Broth

Transdifferentiation

Transdifferentiation is a process by which a non-stem cell transform to a different cell type or when an already differentiated stem cell creates cells that differ from its already engaged differentiation path.

Transduction

Transduction is the integration of exogenous genetic sequences into the host genome via virus particles.

Transfection

The transfer, for the purposes of genomic integration, of naked, foreign DNA into cells in culture. The traditional microbiological usage of this term implied that the DNA being transferred was derived from a virus. The definition as stated here is that which is in use to describe the general transfer of DNA irrespective of its sources, eg cloned genes.

Transformed Cells

Cells that have changed or have been changed in a way that differs to their normal counterparts.

Trophoblast

The trophoblast is the layer of cells that surrounds the inner cell mass and blastocyst cavity.

Trophoectoderm

The trophoectoderm are the cells that form the outer layer of a blastocyst. It provides nutrients for the embryo and also develops into a large part of the placenta.

TSH

Thyroid Stimulating Hormone

Undifferentiated

Undifferentiated cells have not yet developed into a more specialized cell type.

Unipotent

Unipotent cells can merely produce or differentiate into a single cell type.

Variant

A culture exhibiting a stable phenotypic change, whether genetic or epigenetic in origin.

Vector

In molecular biology, a vector is a vehicle that is used to transfer foreign genetic material into another cell. In general, it is a DNA sequence consisting of the insert sequence (transgene) and a backbone sequence. Within the cell, it can now be replicated or expressed. The foreign DNA sequence is termed recombinant DNA, and it usually contains a marker sequence as well. The most commonly used vector is a plasmid.

Vero

The Vero cell line was isolated from kidney epithelial cells of the African green monkey (Chlorocebus sp.). The main use of Vero cells lies in virology, e.g. toxin screening of E. coli, as host cells for virus production or eukaryotic parasites. Vero is a continuous, aneuploid cell line that does not secrete interferon alpha or beta when infected by viruses. This interferon-deficiency can be neutralized with recombinant interferon, as the cells still carry Interferon-alpha/beta receptors. The cells grow anchorage dependent, making them excellent microcarriers for large-scale virus production.

Viral infectivity factor

The Viral infectivity factor (Vif) is a lentiviral packaging element that blocks a cellular inhibitor of viral replication.

Viral protein r

Viral protein r (Vir) is a lentiviral packaging element that participates in the viral RNA into the nucleus for chromosomal integration.

Viral protein u

Viral protein u (Vpu) is a lentiviral packaging element that is localized at the cell membrane, facilitating the viral release.

VITS

Vitamins

WCB

Working Cell Banks

WHO

World Health Organization

Wiskott-Aldrich syndrome protein

(WASP) Protein involved in signal transduction to the microfilament cytoskeleton. Other family members are N-WASP (neuronal Wiskott-Aldrich Syndrome protein) and Scar.

Xenograft

Acronym for xenotropic murine leukemia virus, a virus recently detected in prostate cancers and associated with chronic fatigue syndrome.