Compatibility testing without a centrifuge: the slide Polybrene method.

BACKGROUND A simple and rapid slide Polybrene method (SP) for pretransfusion compatibility testing is described. SP is particularly suitable for use in developing countries where, due to limited resources, centrifuges and biologic reagents may not be readily available. STUDY DESIGN AND METHODS The original manual Polybrene method (MP) was modified for use on glass microscope slides, eliminating the need for test tubes and centrifugation. The sensitivity of SP for detecting alloantibodies to RBC antigens was compared with that of MP and the IAT. RESULTS Both SP and MP were more sensitive than the IAT for detecting anti-E. SP detected 21 of 23 examples of anti'-Mi(a)' and 7 of 8 examples of anti-E. Kidd and Diego system antibodies were also readily detectable by SP, although the reactions were weaker than those observed with both MP and IAT. However, both SP and MP failed to detect some examples of antibodies to Kell system antigens. CONCLUSIONS SP is an acceptable method for compatibility testing in developing countries, particularly in populations where the frequency of K is low (e.g., southeast Asia). The reagents are inexpensive and can be prepared in-house. SP is simple to use, does not require a centrifuge, and can be performed by personnel with minimal training.