(P-BC-86) Validation of an Isoagglutinin Titer IgG Production Pool Screening Assay 1:200 Dilution Program Utilizing a Liquid Handling System

Background/Case Studies: The Isoagglutinin Titer IgG Assay is used for quantifying the levels of antibodies in the blood. These levels vary from person to person and can be utilized to assess an individual’s immune response and is commonly used to monitor the effectiveness of certain treatments like intravenous immunoglobulin (IVIG). A 1:200 dilution program was created as a precursor to running the Anti-A IgG screening assay on the Ortho Vision Swift MAX instrument thereafter. The custom designed program was used to dilute samples at a factor of 1:200 on a high-volume scale using a liquid handling TADM (Total Aspiration and Dispense Monitoring system), with minimal input needed to oversee the instrument while it is in use.

Study

Design/Methods: We worked with the liquid handling instrument engineer to generate a program with the necessary dilution preferences. Several modifications were made to the program as materials, error handling, and general streamlining updates were required for minor monitoring needed from the instrument user. Once completed to specifications, 32 samples were used for gravimetric analysis by diluting saline and aiming to achieve dilution weights that fell between 1.9897-2.0307 grams. Intentional errors were simulated by repositioning barcodes, taping over samples, and loading empty tubes to mimic unreadable barcodes, samples with aspiration errors, and samples with low volume, respectively. The program was assessed for an expected picklist to be available after each run, should any issues occur. A method comparison using 20 samples was conducted to ensure that comparable results were obtained on the Ortho Vision Swift MAX between previously tested samples and samples generated using the dilution program.

Results/Findings: Gravimetrics for 32 saline samples fell within the acceptable range of dilution weights between 1.9897-2.0307 grams after the dilution. Exhibiting the expected results demonstrated that the program was functioning to specified standards. Furthermore, the method comparison of 20 previously tested samples displayed successful findings from the Ortho Vision Swift MAX that were identical ± 1 grade to previous results. The program was able to run with little user interaction and a picklist was available after each run and samples that errored via barcode issues, low volume, or aspiration errors matched that on the picklist.

Conclusions: This study successfully validated the custom 1:200 dilution automated liquid handling TADM (Total Aspiration and Dispense Monitoring system) to prepare samples for testing utilizing an Anti-A IgG screening assay on the Ortho Vision Swift MAX.