Identification of the appropriate tissue from formalin fixed perinatal autopsy material for chromosomal ploidy detection by interphase FISH.

ABSTRACT

We have evaluated the suitability of different formalin fixed paraffin embedded tissues i.e., brain, bone, liver and placenta, for fluorescence in situ hybridization (FISH) efficiency and chromosomal ploidy detection employing directly labelled repetitive sequence probes for chromosome X, Y and 1. The study was carried out on four foetal autopsy specimens. Cells from 50 mu thick tissue sections were dissociated before performing mono and multicolour FISH with directly labelled probes. Hybridization efficiency was maximum with brain tissue (81, 55 and 24% for mono, dual and triple colour FISH, respectively), followed by bone (45 and 34% for mono and dual colour FISH), liver (38, 19 and 0% for mono, dual and triple colour FISH) and placenta (14, 5 and 0% for mono, dual and triple colour FISH). These results indicated that brain is the most efficient material followed by bone, liver placenta for chromosome ploidy detection by FISH in formalin fixed tissues.