The use of directly frozen cells in LDA assay.


A method of direct freezing is described which requires a cryoprotective medium consisting of human AB serum and DMSO, an ultra-low temperature freezer and a liquid-nitrogen refrigerator. Fresh and directly frozen cells were compared in the LDA assay. Direct freezing is quite reliable for normal lymphocytes, PHA transformed lymphocytes or leukaemic blasts… (More)