B-005 Improved Sensitivity on the Beckman Coulter DxI 9000 Immunoassay Analyzer* Enables Reduction of Required Sample and Reagent Volumes for Immunoassays

Background The Beckman Coulter DxI 9000 Immunoassay Analyzer* includes new technology that improves assay sensitivity capabilities. Such technological advancements include the Lumi-Phos PRO chemiluminescent substrate, a new luminometer, and improved low-volume pipetting capabilities. These enhancements afford opportunities to develop immunoassays using reduced sample and reagent volumes, conserving precious patient samples, minimizing the carbon footprint of plastic packaging, and increasing the number of tests per reagent pack. Studies are presented herein for the Access TSH (3rd IS), Access βhCG (5th IS), and Access Hybritech Total PSA assays to evaluate analytical performance when using decreased sample/reagent volumes on the DxI 9000 analyzer. *The official name is DxI 9000 Access Immunoassay Analyzer. Methods To assess performance when using proportionally reduced sample/reagent volumes on the DxI 9000 analyzer compared to standard sample/reagent volumes on the Access 2 Immunoassay System, within-laboratory precision was evaluated following CLSI EP05-A3, limit of quantitation (LoQ) was estimated following CLSI EP17-A2, and accuracy was assessed following CLSI EP09c, 3rd ed. Results Results of sensitivity studies are summarized in the table below for assays using reduced sample/reagent volumes on the DxI 9000 analyzer compared to standard volumes on the Access 2 system. Maximum observed LoQ improved 1.4- to 3-fold on the DxI 9000 analyzer, despite employing ∼50% reduction of sample/reagents. Precision and accuracy studies also showed acceptable performance. Conclusions The data herein provide evidence for maintained analytical performance goals when using reduced sample and reagent volumes for assays on the DxI 9000 analyzer. The additional sensitivity capability of the DxI 9000 analyzer can be used to reduce the volume of sample and reagents, conserving patient samples and reducing packaging per test. The pipetting accuracy and detection capabilities of the DxI 9000 analyzer provide opportunities for immunoassay developers to drive both improved low-end performance and conservation of resources.