Abstract: Objective　To investigate the feasibility of recycle of remaining reagent in Roche E170 automatic electrochemiluminescence immunoassay.  Methods　Alpha fetoprotein(AFP), carcino-embryonic antigen(CEA), carbohydrate antigen(CA)199, CA153 and CA125 in specific sera were detected by remaining reagents and original reagents. The precision， accuracy and recovery rate of remaining reagents were analyzed. The mean values and correlation of the 5 items in 3 different concentrations of sera (low, middle and high levels) were compared by 2 kinds of reagents.  Results　The within-run and between-run coefficients of variation (CV) of the 5 items measured by remaining reagents in low and high levels of sera met the related standard. The accuracy was within the allowance range. The recovery rate was variable from 90% to 110%. Comparing the results of the original reagents with the remaining reagents， there was no statistical significance of 3 different levels of the 5 items (P>0.5).  Conclusions　The remaining reagent can be recycled by Roche E170 automatic electrochemiluminescence immunoassay， which also can ensure the quality of measurement and the reduction of the cost.

Key words: Remaining reagent recycle analysis, Automatic electrochemiluminescence immunoassay, Result analysis