Application of microfluidic chip analytical systems in ABO genotyping / 中国实验血液学杂志

Limitations of polyacrylamide gel or agarose gel electrophoretic methods in genotyping research affect the interpreting of detection results. In order to develop a simple and reliable method for appraising results of ABO genotyping detection, the microfluidic chip analysis system was established by using microfluidic chip to replace the gel electrophoresis and combining with multiplex-PCR-RFLP technique. 150 blood samples were tested by this microfluidic chip analysis system with multiplex-PCR-RFLP technique to evaluate its stability and accuracy. The results showed that all the testing results were consistent with serologic ABO genotyping results and 1 blood sample with decrease of B antigen caused by CML was identified. In conclusion, the established microfluidic chip analysis system is stable and reliable technique. Application of this technique enables the ABO genotyping results to be more objective and accurate.

ABO genotyping of Han population in Beijing / 中国实验血液学杂志

The aim of this study was to establish a diagnostic method for ABO genotyping and to investigate the distribution of ABO genotype in Beijing Han population so as to understand the distribution characteristics and regularity of ABO genotype. An ABO genotyping method was established by using multiplex-PCR-RFLP and PCR-SSP techniques, and the ABO allele frequency in Beijing Han population was investigated. The results showed that A102, O1 and B allele were more common genes in Beijing Han individuals. And A102 allele was predominant in the phenotype A group in this population. Three O2 alleles were found and no A201 allele was found while gene frequency investigation was performed. No A101A101, A101O2, A102O2, BO2 and O2O2 in this population were discovered. It is concluded that the primary regularity of ABO allele distribution in Beijing Han population is found through this study. It provides basic reference for further study of ABO types.

Stability of hepatitis C virus RNA in various processing and storage conditions / 中国实验血液学杂志

The study was purposed to investigate whether processing and storage conditions might influence the stability of the HCV RNA in whole blood or in plasma. The samples obtained from seven patients known to be positive for HCV RNA were kept in different storage conditions with different anticoagulants, and at the end of processing the plasma samples were frozen at -80 degrees C until fluorescent quantitative PCR testing. The results showed that there was no significant loss of HCV RNA titers in whole blood anticoagulated with CPDA or ACD or EDTA or none (P > 0.05), while differences in comparison of the EDTA-anticoagulant storage condition with three other anticoagulants storage conditions at 4 degrees C after 48 hours were significant (P < 0.05). The HCV RNA level decreased to 53.8%, 72.5% and 29.8% after 48 hours of storage of whole blood anticoagulated with ACD at 4 degrees C, 25 degrees C and 37 degrees C respectively. The HCV RNA level of plasma samples stored at 4 degrees C and at 25 degrees C (room temperature) after 7 days decreased to 70.9% and 25.1% respectively. After four freeze-thaw cycles the HCV RNA level decreased 38.9% in plasma samples. It is concluded that the HCV RNA is stable relatively. The HCV RNA is resistant to degradation under routine laboratory handling and storage conditions or blood collection, transport and processing conditions. The influence of different anticoagulants on the stability of HCV RNA is different. Blood samples would better be stored at 4 degrees C after collection and plasma separated within 48 hours. And it is important for the stability of HCV RNA undergoing asepsis blood collection process. HCV RNA remains stable at 4 degrees C for at least 7 days or at room temperature for 3 days, allowing greater flexibility in samples collection and transport in transfusion practice nowadays. HCV RNA in plasma samples subject to up to three short-term freeze-thaw cycles is still stable.

Correlation between signal/cutoff ratios of anti-HCV enzyme immunoassay (EIA) and their true positivity in blood donors / 中华肝脏病杂志

<p><b>OBJECTIVES</b>To evaluate the correlation between signal/cutoff (S/CO) ratios of anti-HCV EIA and their true positivity for determining the predictive value of S/CO ratios.</p><p><b>METHODS</b>One hundred and fifty-nine samples of blood from donors positive for anti-HCV at the initial screening were collected from Beijing, Guangzhou, Hangzhou, Kunming and Urumchi. All the samples were retested by Ortho and 6 Chinese domestic anti-HCV EIA kits in duplicate, and detected for HCV RNA (NAT) using Chiron Procleix HIV/HCV system (transcription mediated amplification, TMA). The HCV RNA negative samples were further tested for anti-HCV by Chiron RIBA 3.0. Either NAT or RIBA positive samples were interpreted as the true positive.</p><p><b>RESULTS</b>All 7 anti-HCV EIA kits had a significant correlation between S/CO ratios and true positivity. The S/CO ratio of Ortho > or = 3.8 predicted the true positivity in 96.1% of the samples tested. The S/CO ratios of BGI-GBI, GWK, SABC, KHB, InTec, and Wantai were > or = 7.0, > or = 10.0, > or = 6.0, > or = 10.0, > or = 8.6, > or = 14.0 and predicted 96.1%, 96.1%, 97.3%, 96.0%, 96.1%, 96.0% of the true positivity, respectively.</p><p><b>CONCLUSIONS</b>The S/CO ratios of anti-HCV EIA kits are associated with the true positivity. S/CO ratios of Ortho, BGI-GBI, GWK, SABC, KHB, InTec and Wantai predicting > or = 95% true positivity are > or = 3.8, > or = 7.0, > or = 10.0, > or = 6.0, > or = 1 0.0, > or = 8.6 and > or = 14.0, respectively.</p>