Reliability of finger stick capillary blood for the lymphocyte micronucleus assay

Compared with peripheral blood sampling, capillary blood collecting by finger stick is less traumatic and more convenient. To assess the sensitivity and reliability of capillary blood for the lymphocyte micronucleus (MN) assay, this study was performed in three sample groups, i.e. healthy donors (n = 3), cancer patients before treatment (n = 7), and cancer patients who were undergoing fractionated partial-body radiotherapy (n = 9). For each group, we measured three intra-individual variables, i.e. micronucleus (MN) frequency, binucleate (BN) index, and micronucleated BN index of lymphocytes obtained from capillary blood and the corresponding peripheral blood. Our results indicated that in all three sample groups, the differences in these variables between capillary blood and peripheral blood either before or after ex vivo 137Cs irradiation (2 Gy) were insignificant. Since capillary blood is more accessible than peripheral blood, we believe that it is a reliable source for the lymphocyte MN assay especially when venipuncture is not convenient.