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@#Objective To develop a kinetic chromogenic quantitative method for the determination of endotoxin content in intermediate of pertussis antigen,and to verify the method so as to better control the quality of diphtheria,tetanus,and pertussis vaccine(DTP vaccine).Methods A kinetic chromogenic assay[Limulus Amebocyte Lysate(LAL)]was developed to detect the endotoxin content in the intermediate products of pertussis antigens after detoxification,and verified for the linearity,specificity,accuracy,reproducibility and intermediate precision. The quantitative detection results of kinetic chromogenic assay were compared with those of gel method.Results The absolute value of the linear correlation coefficient（|r|）of the kinetic chromogenic assay was more than 0. 99;under the maximum effective multiple dilution,the interference test recovery of the intermediate was within 50% — 200%,and pertussis toxin(PT)diluted to 10,100 and 1 000 times,filamentous hemagglutinin(FHA)diluted to 3 000,5 000 and 10 000 times,and pertussis adhesin(PRN)diluted to 50,75 and 100 times had no interference effect on the experiment after detoxification;the accuracy verification recovery rates of PT,FHA and PRN were 125%,110% and 99% respectively;and the CVs of reproducibility verification were 7. 21%,8. 31% and 5. 84%,and the CVs of intermediate precision verification were 6. 04%,16. 29% and 12. 23%,respectively.The bacterial endotoxin content of the three batches of pertussis antigen intermediates detected by kinetic chromogenic assay was consistent with that verified by gel method,both of which were less than the limit of bacterial endotoxin in the intermediates of pertussis antigen after detoxification.Conclusion The developed kinetic chromogenic assay has good linearity,specificity,accuracy and precision with accurate detection results,which can be used to detect the endotoxin content in intermediate products of component pertussis antigen after detoxification.
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Aim To evaluate the equivalence between micro kinetic chromogenic assay anrl kinetic chromogenic assay in order to provide data support for the use of alternative methods.Methods Detection conditions; micro kinetic chromogenic assay and kinetic chromogenic assay limulus reagent were used, sample amount of each well and limulus reagent was 25 jxL ( kinetic chromogenic assay was 100 jxL) , detection wavelength was 405 nm, ONSET OD value was 0.03, and half- well elisa plate was used for detection ( kinetic chromogenic assay was ordinary ELISA plate).The equivalence of the two methods was evaluated by various statistical methods, such as equivalence test, in collaboration with four laboratories in China.Results The results of one-way an OVA, paired T test and equivalence test were consistent, indicating that there were some differences between the existing kinetic chromogenic assay of different manufacturers, while there was no significant difference between the trace or conventional amount of reagent used by each manufacturer.Conclusions Micro kinetic chromogenic assay is e- quivalent to existing reagents in terms of accuracy and recoverv.J.