Effects of delays in peripheral blood processing, including cryopreservation, on detection of CD31 expression on naive CD4 T cells

Delayed processing of peripheral blood or peripheral blood mononuclear cell isolation and cryopreservation can lead to the detection of somewhat higher levels of CD31 expression on naïve CD4 T cells by flow cytometry. These observations should be considered in the planning of multicenter clinical trials and in the interpretation of the results of functional studies.