Fluorescence in situ hybridization analysis of human oocytes: Advantages of a double-labeling procedure

Abstract

To improve the fluorescence in situ hybridization (FISH) chromosomal analysis of human oocytes and first polar bodies. In situ chromosomal identification on isolated cells, with combinations of centromeric (or locus-specific) probes and whole-chromosome painting probes for chromosomes 9, 13, 16, 18, 21, and X. Montpellier University Hospital. Women participating in an IVF program. Fifty-four in vitro unfertilized oocytes were fixed on slides, and simple or double FISH labeling procedures were performed on preparations. Simultaneous in situ visualization of specific domains and chromosome arms of each targeted chromosome. Eight chromosomal abnormalities were identified, including two hyperhaploidies, three cases of extra single chromatid, and three cases of balanced separation of sister chromatids. Also, the double-labeling procedure allowed the avoidance of five interpretation errors, owing to additional artefactual signals. By ensuring precise identification of both chromosomes and single chromatids, the FISH double-labeling procedure limits the risk of erroneous interpretation and allows a more accurate cytogenetic analysis of human oocytes.