Medical Journal of The Islamic Republic of Iran (MJIRI)

 Abstract

 Background: To produce a reliable probe suitable for aneuploidy detection of chromosome

 13 on uncultured lymphocytes and amniocytes by fluorescence in situ hybridization

 (FISH), we used a contig of three overlapping cosmids mapped to 13q12.3.

 Methods: The cosmid DNA carrying the expected sequences of human chromosome 13

 was isolated from host cells and labelled with biotin-11-dUTP. The hybridization and detection

 conditions with FITC-Avidin were optimised using a series of cultured and uncultured

 lymphocytes and amniocytes.

 Results: Intensive signals were detected when a combination of three overlapping cosmids

 was used to enumerate the chromosome 13 on interphase nuclei. An average of 87

 and 85.5 percent of interphase cells prepared from lymphocytes and amniocytes showed

 accurate number of specific signals for chromosome 13.

 Conclusion: The results obtained in present study indicate that the probe was capable of

 detecting the copy number of chromosome 13 on interphase cells prepared from peripheral

 blood or amniotic fluid cells providing that the uncultured amniotic fluid cells are free of

 cytoplasmic residues, RNA and protein debris.