Human stem cells are valuable commodities: as well as their medical potential, their pristine naivety makes them attractive as gold-standard cell lines for research. Stem-cell banks, where owners deposit their precious products and would-be investigators apply for loans, are now being developed.

The most advanced is the UK Stem Cell Bank, based at the National Institute for Biological Standards and Controls in Potters Bar, near London. Initiated in September 2002, and funded by the Medical Research Council and the Biotechnology and Biological Sciences Research Council since January 2003, it has the aim of providing a repository for all types of human stem-cell lines.

“As of October 2005, we have 24 stem-cell lines approved for accession into the bank,” says director Glyn Stacey, but none is yet ready for sending out to end-users. That probably won't be until early 2006. “The process is complex. It is not like growing an ordinary cell line where you could create and quality control a bank within a few months of receiving the cells,” says Stacey. One time-consuming step is the creation of agreements for depositers and recipients, with each cell type presenting different problems and opportunities. Exploitation will be controlled by the depositer who retains ownership of the cells.

Legal issues aside, stem cells are challenging to grow. The main problem is scaling up to provide hundreds of ampoules of cells at identical passage levels and stages of differentiation. “It could take an entire day for a highly skilled person to dissect and recover cells from just one line,” says Stacey. And cultures have to be characterized and checked for contamination before release.

Glyn Stacey: stem cells are challenging to grow. Credit: MRC

All lines currently in the bank are human embryonic stem (ES) cells. “We have had some contact with people who think they have adult stem cell lines, but they are being careful about characterization,” says Stacey.

A few ampoules of each cell line have been frozen as back-up, whereas the master bank contains 20 or 30 ampoules. The distribution stock may eventually contain around a hundred ampoules of each line. Stacey hopes that early in 2006 the bank's website will start tracking progress of the cell lines that will be available to researchers.

A few other initiatives are taking shape. The US National Stem Cell Bank will be located at the WiCell Research Institute, in Madison, Wisconsin, with a $16.1 million, four-year National Institutes of Health grant. It will acquire, store, characterize and distribute human embryonic stem-cell lines, but will be limited to those approved for federal funding. After a year of legal wrangling, a stem-cell bank is taking shape at the University of Granada in Spain, and others are being considered in Australia and South Korea.

P.M.