Study on the quality control of operating problems in ELISA

Abstract

Objective To approach the feasibility of studying the general operating problems in ELISA with the quality control method.Methods Ninty-four serum samples with HBcAb(-)were collected for the assay. The difference between the two different procedure of the competitive immunoassay was observed. With the CEA kit， we retrospectively assessed the quality control of the key points of the ELISA procedure. We summarized the results of 15 different production lots of the CEA standards serum and figured out the interassay CV. We chose the sera with CEA level ranged 5.0-5.5 ng/ml and calculated the mean value， SD and CV of the 45 lots of kits.Results It showed that the results were significantly different between the two methods on assaying the HBcAb(P<0.01).There was no false-positive by the alternative sample-adding， but 17.02%(16/94)false-positive by the orderly sample-adding. At the standard value of 0,2,5,15,50,75 ng/ml， the standards curve of CEA of the 15 different production lots were statistically analyzed. The CVs of the OD620 were 11.8%,11.8%,9.22%,8.78%,8.46% and 4.23% respectively. The CV value reflect the general skill of the operator under the routine condition of the lab. The cut-off value of the serum CEA was corrected by the test of 45 lots， and the CV was only 3.68%(0.3633±0.0134).Conclusions The alternative sample-adding method in ELISA might reduce the rate of the false positive； Quality control of the key points of the procedure of ELISA could ensure the accuracy of the test.