Influence of mixing parameters in STAR automatic sample processing instruments on the detection results of internal controls

Abstract

Objective To explore the significance of blending internal controls by automatic sample processing instruments in the enzyme linked immunosorbent assay (ELISA). Methods The internal controls were vortexed and mixed before the test, and then were added to the same ELISA plate by the STAR automatic sample processing instruments under the same detection conditions. The difference of S/CO value of internal controls with and without sufficient blending via the sampling needle and their frequency distribution were compared. Internal controls that were greatly affected by mixing parameters were submitted to the same test with different batches of reagents from the same manufacturer, and the results were analyzed for consistency. Results The S/CO value of anti-HCV internal controls without blending using adding sample needle was significantly lower than that of quality control samples with sufficient blending (P<0.000 1). The S/CO values of unmixed internal controls concerning anti-TP and anti-HIV detection given by some detection systems were also different from the values of mixed internal controls (P<0.05). Some of the S/CO values of the anti-HCV internal controls without mixing were distributed within the interval of less than 2. Different batches of reagents from the same manufacturer were used to detect anti-HCV internal controls, and there were differences in the partial detection values between the mixed and unmixed internal controls (P<0.05). Conclusion Although the internal controls were mixed by vortex shock before the test, the detection results of some internal controls will still be affected when the STAR automatic sample processing instruments does not set the mixing parameters for internal controls.

Keywords

• automatic sample processing instruments
• mixing parameters
• enzyme linked immunity
• internal controls