Evaluation of the impact of carryover in a fully automated, high-sensitivity hepatitis B core-related antigen assay

We developed and reported a fully automated, high-sensitivity hepatitis B core-related antigen assay (iTACT-HBcrAg). This study aimed to evaluate the impact of carryover during the use of iTACT-HBcrAg by analyzing samples with high HBcrAg levels. A negative sample tested immediately after a sample with an HBcrAg of 8.7 LogU/mL showed an HBcrAg of 2.4 LogU/mL, thus confirming carryover. The sample with an HBcrAg of 8.8 LogU/mL and collection tubes containing the negative samples were continuously opened to check for the effects of sample splashing and aerosols. The results showed that sample splashing and aerosols did not account for the carryover. The iTACT-HBcrAg is a highly sensitive assay; therefore, carryover can occur when magnetic particle-antigen complexes are introduced into the next sample via the BF wash nozzle. Any sample determined to be positive for HBcrAg after the testing of a sample with an HBcrAg above the measurement range should be retested for confirmation.