The effects of 21 cytological and nucleic acid binding dyes on autosomal and Y-chromosomal STR markers using new generation STR amplification kits

Abstract

Before DNA fingerprinting analysis, many biochemical and histopathological testing are conducted on a forensic biological sample. The samples are exposed to cytological and nuclear binding dyes for their visualization under a microscope. The present study assessed the usability of these biological samples exposed to 21 routinely used histological and nuclear binding dyes for forensic DNA examination in a simulated experiment. Wright's stain, Hematoxylin, Coomassie Brilliant Blue, and Evan's Blue did not show any effect on the amplification of autosomal STR markers. Y-STRs showed higher robustness in presence of 10 dyes. Wright's stain showed the least effect on the generation of complete autosomal and Y-STR profiles. Mobility issues in capillary electrophoresis were observed in the presence of Eosin yellowish, Coomassie Brilliant Blue, and Hematoxylin for autosomal STRs and Wright's stain, Orcein, Malachite Green, Nigrosin, Bromophenol blue, and Fast green for Y STRs. Peak heights of the respective Y STR markers showed a mixed result in comparison to the positive control. In autosomal STR analysis, the peak heights showed a sharp decrease in comparison to the positive control.