Study on the internal quality control of TGAb and TMAb RIA in clinical laboratory

To investigate the possible causes of the occasional instability of thyroglobulin anti- body(TGAb) and thyroid microsome antibody (TMAb) detection in the laboratory, the control serums of low, middle, and high value of different batches were measured and the stability of the labeled antigens stored at 2-8 degree C and below zero was observed. The results showed that the maximal variances of high value control serums for TGAb and TMAb between different batches were 33.0% and 32.5%, respectively. This was caused by the changes of titer of second anti- bodies. The labeled antigens stored below zero showed better stability. The strict internal quality control is an efficient measure to improve the measurement precision. (authors)