AlloHeme is a blood-based monitoring test developed by the CareDx laboratory that utilizes NGS technology coupled with a proprietary algorithm to predict the likelihood of a relapse in post-allo-HCT AML/MDS patients. The technology analyzes 405 single nucleotide polymorphisms (SNPs) selected from across all somatic chromosomes between the donor and the recipient. Pre-transplant DNA is obtained from donor and/or recipient to identify specific donor and recipient SNPs (baseline samples). Post-transplant blood samples are obtained and compared to the baseline sample profiles to precisely calculate the percentage chimerism of recipient cells in the blood samples using a proprietary quantitative method and unique dual indexing that optimizes recipient DNA at trace levels. This approach enables highly accurate and reproducible chimerism measurement with a limit of detection down to 0.02%. The AlloHeme test leverages a proprietary algorithm that integrates this multi-analyte longitudinal chimerism data with post-transplant time points to predict the likelihood of a clinical relapse for AML/MDS patients following an allo-HCT.