Evaluation of an automated technique for assessment of marrow engraftment after allogeneic bone marrow transplantation using a commercially availablekit

Several methods have been used to evaluate engraftment after allogeneic bon e marrow transplantation (BMT). We assessed the usefulness of a multiple sh ort tandem repeat (STR) amplification kit combined with a capillary electro phoresis unit for DNA identity analysis in the evaluation of engraftment af ter BMT For 17 of 18 patients, at least 1 locus showed unique alleles for t he donor and the recipient. In all cases, at least 1 locus was informative for the presence of small amounts of recipient DNA. The results from STR an alysis were the same as Southern blot analysis in 14 of 17 cases. Differenc es included mixed chimerism detected only with STR analysis, informative lo ci present only with STR analysis, and informative loci present only with S outhern blot analysis (1 case each). By using mock mixed chimeras, minor po pulations of 5% were detected routinely in all loci using the kit manufactu rer's default protocol. By increasing the amount of amplified DNA, minor po pulations of 5% were detected in all cases but not in all loci. This single reaction technique provides for faster results, reduced workforce needs, a nd greater sensitivity than traditional Southern blot.