Sample viability with Flow Cytometry is of the utmost importance. For example, if a shipment is delayed or if a specimen is held overnight, please do not put it in the refrigerator. Instead, add 1:1 RPMI fluid to the specimen and hold overnight at room temperature.

We find that under these conditions, the specimen stays viable for 4-5 days. We instruct our International Clients to do this protocol all the time. This allows the cells to get some glucose but does not shock them with a cold temperature and contributes to potentially erroneous results.