Abstract The DriverMap™ Adaptive Immune Receptor (AIR) repertoire profiling assay employs multiplex RT-PCR for comprehensive profiling of CDR3 or full-length receptor profiling of all variable heavy and light chains of T-cell receptors (TCR) and B-cell receptors (BCR) from either RNA or DNA. In this study, initiated by a U.S. Food and Drug Administration (FDA) consortium to compare performance of different BCR repertoire profiling technologies, we tested spike-ins in peripheral blood mononuclear cell (PBMC) RNA and DNA control mixtures prepared from nine different B-cell lines. We measured the sensitivity, linearity and accuracy of AIR RNA and DNA BCR profiling for the IGH, IGK and IGL chains of the spike-in controls. Our comprehensive analysis, encompassing CDR3 profiling and full-length receptor profiling (CDR1, CDR2, and CDR3) sequencing, revealed a 100X increase in sensitivity of detection of spike-in controls in RNA compared to the DNA assay. The high sensitivity of the full-length DriverMap AIR RNA assay allowed the detection of controls from all nine cell lines, with 8 out of 9 cell lines detected in the DNA assay, which demonstrates the robustness of the DriverMap AIR profiling technology. This study highlights the remarkable sensitivity of the AIR RNA assay in quantifying transcripts. This approach enables the detection of low-frequency BCR clonotypes, which is particularly advantageous when working with samples containing low numbers of B cells. Furthermore, our AIR DNA assay in combination with spike-in controls offers a quantitative tool for minimal residual disease (MRD) applications, providing accurate insight into cell numbers, which then facilitates tracking clonal expansion of immune cells. Citation Format: Alex Chenchik, Tianbing Liu, Mikhail Makhanov, Dongfang Hu, Khadija Ghias, Paul Diehl. Evaluation of BCR spike-in controls using DriverMap adaptive immune receptor (AIR) profiling technology [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 791.