RESUMO
@#Objective To prepare the national reference panel of hepatitis B virus(HBV) for nucleic acid testing(NAT)donor screening.Methods A number of plasma samples from donors positive for HBV antibody and patients with HBV infection collected from blood centers,plasma stations and biological products companies in Shanghai,Gansu,Henan,Hunan,Hubei and other regions were tested for HBV DNA viral load agent,and negative and positive reference candidates were screened;The HBV DNA national standard was diluted to 10~3 IU/ml with human negative plasma,as a candidate for limit of detection(LOD).National negative and positive reference candidates of HBV for NAT donor screening and LOD reference to be calibrated were distributed to 8 enterprise laboratories for joint detection of HBVHCVHIV NAT donor screening.The homogeneity and stability of the national reference panel were investigated.Results A total of 8 negative samples with HBV viral load of 0 were screened as negative references and 9 positive samples with viral load of 10~3～10~4 IU/mL were used as positive references;One LOD reference was calibrated with WHO HBV DNA standard,and the virus content was 1.0 × 10~3 IU/ml.The national reference panel showed good stability and the homogeneity inspection met the requirements.Conclusion The national reference panel of HBV DNA for NAT donor screening was prepared,which provided a basis for the quality control and standardization of HBV DNA reagents for donor screening.
RESUMO
Objective To explore colloidal gold method used to detect fecal occult blood tests(FOB)detection capability and establish the laboratory standard operation of detecting FOB limit of blank(LOB),limit of detection (LOD)and quantifica-tion limit (LOQ)according to the CLSI document《Evaluation of Detection Capability for Clinical Laboratory Measurement Procedures;Approved Guideline-Second Edition》(EP17-A2),in order to reduce the false negative rate of the weakly positive samples,and to provide a way of quantitative detection for qualitative detection of colloidal gold method.Methods Detected series of solution of hemoglobin made of dissolved fresh whole blood with the ELISA kit of human free hemoglobin,and es-tablished the standard curve of detection of FOB with colloidal gold method.Detected the blank samples and a series of low concentration samples with the colloidal gold test strip of FOB and measured the color bands by the Nato Checker710.The quantitative results obtained were statistically analysised by SPSS 1 9.0 and calculated blank limit,detection limit and quanti-fication limit.Results The LOB,LOD and LOD were 99.01,340.48 and 354.9 ng/ml according to the methods in CLSI EP1 7-A2 ducument.Conclusion The detection limits established by CLSI EP1 7-A2 document was more scientific in j udge-ment positive or negative to FOB than which used naked eye and can meet the clinical laboratory and clinical doctor require-ment better.Clinical laboratories should be strictly in detection limits of reagents in order to ensure their effectiveness,and should be generaly to other tests based on colloidal gold method.