Recommended methods for the assignment of assay values to stabilized cell suspensions.

Stabilized blood suspensions are required for the transfer of data from accurately calibrated reference instruments to service laboratory instruments. However, the more the cells are stabilized to increase shelf life, the less like fresh blood they become. Fixation is quite satisfactory for producing red count standards but it affects the flexibility, shape factor and the assigned MCV of the erythrocytes. Because of these problems values must be assigned indirectly by assigning values to fresh blood by reference methods and subsequently comparing fresh bloods with stabilized suspensions on a range of user instruments. The details for these methods are given and the reasons for these requirements are discussed.