Polymerase chain reaction for the detection of methylation of a specific CpG site in the G6pd gene of mouse embryos.

This chapter describes the polymerase chain reaction (PCR) detection of methylation changes at specific CpG sites in DNA isolated from minute quantities of biological material, such as single preimplantation mouse embryos or small numbers of stem cells, or germ cells. We have concentrated on refining these techniques to monitor specific sites in X-linked genes for methylation changes associated with X-chromosome inactivation. The general principles of the HpaII-sensitive PCR assay described here should be applicable and adaptable to specific CpG sites in other genes of interest.