4.0 Sourcing of Cell Lines
Large numbers of cell lines look identical. Cell lines with very different origins and biological characteristics typically cannot be separated on grounds of morphology or culture characteristics. Infection or contamination of a cell line with an adventitious virus or mycoplasma may significantly change the characteristics of the cells but again such contamination will be inapparent. Cell lines will also change with time in culture, and to add to all these natural hazards it is all too easy to mis-label or cross-contaminate different cell lines in a busy cell culture laboratory.
The opportunities for inadvertently introducing error into a cell line are limitless and ever present. It is in the nature of the science that, once introduced, an error will be propagated, compounded, consolidated and disseminated.
The integrity and biological characteristics of a cell line have to be actively maintained by a well-organized system of “husbandry” based on systematic cell banking supported by testing regimens in a structured quality assured environment. Such a controlled environment will only prevail in a dedicated professionally organized cell culture laboratory or cell bank. A small research laboratory with a high throughput of short-term research students, a minimum of permanent laboratory staff and no formal quality management program will find it difficult to maintain its cell lines unchanged over many years.
For all these reasons it is strongly recommended that new cell lines should only be acquired from a specialist, reputable culture collection such as ECACC. Moreover, if a laboratory believes it already has a certain cell line in its liquid nitrogen store, the identity and purity of such a cell line should be questioned in the absence of a well-recorded culture history and recent test data. If there is a doubt, it is straightforward and cost effective to replace such cell stocks with authenticated material from a Culture Collection.
When a Cell Culture Collection “accessions” a new cell line it will characterize the cell line using techniques such as isoenzyme analysis and DNA profiling so that the identity of the cell line can subsequently be verified. The Collection will then establish a hierarchy of Master and Working cell banks, cryopreserved in liquid nitrogen, that are demonstrated free from microbial contamination including mycoplasma. Customers are supplied from these authenticated Working Cell Banks (WCB). Replacement WCB's are manufactured from the original Master Cell Bank (MCB) and the new WCB will again be fully tested.
ECACC supplies its cell lines together with advice on how to maintain the line. A Technical Support team will subsequently assist with any difficulties and can often provide additional technical information about the cell line. Culture Collections exist to ensure that animal cell research is conducted using standardized, authenticated material that ensures the work can be reproduced. An authenticated cell line of known provenance is the very "bed rock" of any cell based project.
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