Detailed chromosomal and molecular genetic analysis of single cells by whole genome amplification and comparative genomic hybridisation

Molecular genetic analysis of isolated single cells and other minute DNA sa mples is limited because there is insufficient DNA to perform more than one independent PCR amplification. One solution to this problem is to first am plify the entire genome, thus providing enough DNA for numerous subsequent PCRs. In this study we have investigated four different methods of whole ge nome amplification performed on single cells, and have identified a protoco l that generates sufficient quantities of DNA for comparative genomic hybri disation (CGH) as well as more than 90 independent amplification reactions. Thus, numerous specific loci and the copy number of every chromosome can b e assessed in a single cell. We report here the first reliable application of CGH to single cells from human preimplantation embryos (blastomeres) and to single fibroblasts, buccal cells and amniocytes.