P024 Automated solid-phase HLA antibody assay using the BioTek ELx50 microplate washer

Abstract

Aim Our laboratory currently uses the manual method to perform the wash steps of the Luminex-based single antigen bead (SAB) assay for HLA antibody analysis. Automation of the wash steps using an automated microplate washer with a vacuum filtration module could be beneficial by reducing tech-to-tech variability and hands-on time. The goal of this study was to investigate the use of this instrument toward the automation of the SAB assay. Methods 5 well-characterized samples with antibody profiles containing both HLA Class I and Class II specificities were analyzed in duplicate within run and on 3 separate runs by means of the LABScreen SAB assay (One Lambda, Inc.). Tests were performed with the BioTek ELx50 microplate washer (BioTek Instruments, Inc.) with a MultiScreen 96-well filter plate with a 1.2 μm low protein-binding Durapore membrane (EMD Millipore Corp.), which performed all wash buffer dispensations, aspirations and incubations. The acquisition was performed on the same Luminex 100 instrument. The results obtained with the microplate washer were compared to results obtained using the manual method. Calculations of % coefficient of variation (CV%) were adapted from the NCCLS global consensus guidelines. Results The BioTek ELx50 microplate washer showed consistent results in comparison with the manual method. The MFI CV% values for each sample within run and between run was calculated. No well failures were observed and antibody strength specificities assignments were comparable in all samples. In addition, antibody specificities (MFI > 2000) showed similar MFI and CV% values between the manual and BioTek ELx50-washed samples. Conclusions We have demonstrated the ability of the BioTek ELx50 microplate washer to automate the LABScreen SAB assay. Automation using this microplate washer speeds processing, improves washing efficiency, increases sensitivity and improves accuracy by eliminating tech to tech variability.