Application Note: Absolute Count Data From Streck Cell Preservative Treated Cells

By Dominic Warrino, Ph.D, Mary Hanson, B.Sc. , Amanda Miller-Lindholm, Ph.D.

Absolute CD4+ cell counts are used to help detect and monitor infection and disease, as well as to evaluate the progress of drug treatment. However, the NCCLS requires that blood specimens be analyzed by flow cytometry within 48 hours, and no longer than 72 hours post-collection. It can be difficult to process samples within this time frame, especially if transportation is required.

Streck Cell Preservative is a cellular preservative and transport reagent for whole blood that stabilizes the cell-surface antigens on white blood cells for immunophenotyping by flow cytometry for up to seven days. Streck Cell Preservative is added to peripheral blood in a 1:1 (v/v) ratio of reagent to blood or tissue. Streck Streck Cell Preservative increases the laboratory's options for sample transportation and processing; however, standard methods to obtain absolute counts from the flow cytometer do not allow for dilution of the sample. We investigated whether a dilution with Streck Cell Preservative compromises the absolute cell count data generated via single platform technology.