Use of Single Nucleotide Polymorphisms (SNP) and Real-Time Polymerase Chain Reaction for Bone Marrow Engraftment Analysis

Allogeneic bone marrow transplant engraftment assays use polymorphisms in the human genome to determine the relative percentages of donor and recipient cells present in the recipient. We describe a novel posttransplant assay approach using single nucleotide polymorphisms (SNPs), the most common type of polymorphism in humans. Using samples of defined genotype, we used real-time polymerase chain reaction (PCR) and allele-specific fluorescent TaqMan probes to assay a SNP of the cytochrome P450 CYP2C9 gene. Standard curves of chimeric mixes showed a linear relationship between the ratio of two alleles and the ratio of their respective fluorophore emission, except for mixes with a low percentage (