Detection of mice homozygous for the EPCR R84A mutation by PCR. (A) Schematic diagram of PCR strategy to detect WT or R84A DNA. LoxP sites are represented by single triangles and FRT sites by double triangles. The R84A point mutation in exon 2 is represented by an asterisk (*). PCR amplification of WT genomic DNA results in the detection of a 174-bp fragment, whereas flippase (Flp)-excised genomic DNA yields a 292-bp fragment including an flippase recognition target (FRT) and loxP site. (B) Mouse genomic DNA containing the EPCR Flp-excised allele was tested by PCR. PCR without DNA template (H₂O) was used as a negative control.