PRESERVATION OF CYTOPLASM IN THE HUMAN LYMPHOCYTE MICRONUCLEUS ASSAY

A major limitation in the quantitative accuracy of the human lymphocyt e micronucleus (MN) assay is preservation of the cytoplasm during the cell harvesting. In this short communication, an improved method for c ytoplasm preservation in a cytokinesis-blocked, whole-blood microcultu re (0.3 ml) technique is described. We believe that the timing of the hypotonic treatment, speed of centrifugation, handling of the cell sus pension and proper Giemsa staining are important variables in the huma n peripheral lymphocyte MN assay.