Magnetic-activated cell sorting (MACS) significantly decreases the hybridization efficiency of fluorescence in situ hybridization (FISH)

Fetal cells were enriched from maternal blood using density gradient centri fugation of Histopaque followed by magnetic-activated cell sorting (MACS) t o select CD71-positive cells. For each specimen, cells partially purified b y Histopaque were split into equal portions, and each portion was subjected to purification by MACS in parallel. Cells before and after MACS were subj ected to dual-color fluorescence in situ hybridization (FISH) analysis with X- and Y-chromosome-specific probes. We found that the hybridization rates were decreased by approximately 10% after MACS based on duplicated analysi s for each sample. Copyright (C) 2001 John Wiley & Sons, Ltd.