| abstract |
Cells are treated to preserve them in non-frozen hydrated form with minimal alterations to their antigens or nucleic acids. This makes the cells useful as quality control (QC) reagents for processes such as calibrating and standardizing flow cytometry equipment, for use as "unknown" test samples for QC testing programs, and to prepare patient specimens for archival storage. This method includes: (1) treating the cells to inhibit proteolysis, preferably using several protease inhibitors; (2) fixing the cells, either by contacting them with a crosslinking agent such as formalin or paraformaldehyde, or by exposure to microwave radiation, while the cells are being agitated to promote the formation of crosslinking bonds within a single cell while inhibiting the formation of cell clumps; and (3) if the cells are treated with a chemical crosslinking agent, removing the crosslinking agent and contacting the cells with a quenching agent. The cells should be stored in a solution containing protease inhibitors. This method causes little or no detectable alteration of antigenic or DNA histograms. It has been used to preserve cells that have been stored for months at room temperature, or for more than a year at refrigerated temperatures, with no substantial deterioration of surface or cytoplasmic antigens or DNA content. |