Analysis of Sperm Aneuploidy by PRINS

Based on the direct in situ mixing of the colors of different fluorochromes (fluorescein isothiocyanate, tetramethylrhodamine isothiocyanate, Cascade Blue) incorporated in sequential primed in situ labeling (PRINS) reactions, a new multicolor PRINS procedure is described, allowing the rapid and distinct in situ labeling of three or four human chromosomes. Each PRINS reaction consists of a unique 5-min step for annealing and elongation. In combination with the 0.5 M NaOH pretreatment for simultaneous in situ denaturation and decondensation of sperm nuclei, this technique has been adapted to human sperm nuclei for the direct assessment of aneuploidy.