Abstract: OBJECTIVE: In humans, aneuploidies occur in at least 5% of all clinically recognized pregnancies, among which about 90% can be caused by maternal meiotic error. In this study, a stable and simple method for fluorescence in situ hybridization (FISH) with human oocyte chromosomes was developed to explore causes of maternal meiotic error, mechanisms of aneuploidy and genetic effects of environmental factors on human oocytes. METHODS: The abandoned human oocytes were collected from IVF patients who signed consent forms. The oocytes were used to prepare chromosomal karyotype through hypotonic and gradual fixative treatments. Human oocyte metaphase FISH was performed using the CEP 16 Probe. RESULTS: From our observations, the morphology and dispersal of human oocyte chromosomes were excellent, and the fluorescence signals were bright and clear with clean background. CONCLUSION: We established successfully the method for FISH with human oocyte chromosomes.

Key words: human oocyte, chromosome, fluorescence in situ hybridization, meiosis error, aneuploidy