Seven-layer analysis model of an optical waveguide excitation fluorescence microscopy.

In this paper, an optical waveguide evanescent field fluorescence microscopy is studied. Based on Maxwell's equation, a seven-layer theoretical analysis model is developed for the evaluation of an optical waveguide excitation fluorescence microscopy. The optical waveguide excitation fluorescence microscopy structure is systematically and comprehensively analysed at the wavelengths of 488, 532 and 646 nm for fluorescent dyes. The analysis results provide some useful suggestions, which will be beneficial to the research of an optical waveguide evanescent field fluorescence microscopy.

[Real-time fluorescent quantitative PCR for detection of peripheral blood T-cell receptor excision circles].

OBJECTIVE: To develop and optimize real-time fluorescence quantitative PCR (FQ-PCR) with the housekeeping gene RAG2 as cell number control to quantify T-cell receptor excision circle (TREC) in the peripheral blood. METHODS: The real-time PCR system for amplifying TREC and RAG2 genes was established on the basis of ABI 7000 apparatus using Golden Taq system, designed primers, TaqMan-MGB probes and optimized buffer. PCR conditions were optimized with standard samples of TREC plasmid. RESULTS: The amplification with the primer pair T(3) and T(4) was more efficient than that with T(1) and T(2). More specific and efficient amplification in FQ-PCR was achieved using TaqMan-MGB probes as compared with general Taq-Man probes. Golden Taq was more effective than general Taq in improving the specificity and decreasing the artifact, and 95 degrees C; for 10 min, 95 degrees C; for 5 s, and 53 degrees C; for 30 s for a total of 40 cycles using ABI7000 was found as the optimized thermal parameter setting. CONCLUSION: An optimized real-time PCR protocol for detecting TREC in peripheral blood mononuclear cells is established.

[With genechip technique to investigate HLA-DQB1 gene polymorphisms in south and north regions of China].

OBJECTIVE: To research and compare HLA-DQB1 gene frequency(GF) and polymorphism distribution between south and north population of Chinese in China. METHODS: Combining PCR-sequence specific primers(SSP) and sequence specific oligonucleotide probe(SSOP) techniques and DNA Microarray Kit for HLA-DQB1 Low Res Genotyping from Shenzhen Yi-Shengtang Biological LTD. Co. was used to type HLA-DQB1 gene polymorphisms of 700 individuals living in south China and 320 individuals in north China. RESULTS: We inspected 10 alleles of HLA-DQB1 and got a series of comprehensive and accurate statistic data. CONCLUSION: It is tested that HLA-DQB1*02, 05, 0601, 0602, 0603 gene frequencies are different obviously(P<0.05) between south and north Chinese. And those data will be useful to kinds of research associated with disease relevant and anthropology research.

[Comparative studies of serological typing and HLA-A, B antigen genotyping with PCR using sequence-specific primers].

OBJECTIVE: To evaluate the accuracy of PCR with sequence-specific primers (PCR-SSP) for HLA-I genotyping and analyze the causes of the errors occurring in the genotyping. METHODS: DNA samples and were obtained from 34 clinical patients, and serological typing with monoclonal antibody (mAb) and HLA-A and, B antigen genotyping with PCR-SSP were performed. RESULTS: HLA-A and, B alleles were successfully typed in 34 clinical samples by mAb and PCR-SSP. No false positive or false negative results were found, and the erroneous and missed diagnosis rates were obviously higher in serological detection, being 23.5% for HLA-A and 26.5% for HLA-B. Error or confusion was more likely to occur in the antigens of A2 and A68, A32 and A33, B5, B60 and B61. CONCLUSIONS: DNA typing for HLA-I class (A, B antigens) by PCR-SSP has high resolution, high specificity, and good reproducibility, which is more suitable for clinical application than serological typing. PCR-SSP may accurately detect the alleles that are easily missed or mistaken in serological typing.

[Method of detection of soluble HLA-I and soluble HLA-I level alteration in storage blood].

Aim of this study was to develop the detection method of soluble human leukocyte antigens I (sHLA-I) and to explore sHLA-I level alteration in storage blood and its significance. sHLA-I level in sera of 60 Guangdong normal individuals and sHLA-I concentration in blood components from 20 donors quantitatively were detected by sandwich ELISA. The results showed that sensitivity of this assay was 2.84 ng/ml. Coefficients of variation were 5.80% within assays and 9.00% between assays respectively. The recovery rate was >/= 98.57%. The sHLA-I level of normal individuals in Guangdong was (699.54 +/- 360.10) ng/ml. sHLA-I in red blood cells stored for 28 days and in random-donor platelets were significantly higher than that in other blood components and their amount was proportionate to the number of residual donor leukocytes and to the length of storage. In conclusion, sandwich ELISA assay for detection of sHLA-I is a sensitive, specific and stable technique. Blood components with different concentration of sHLA-I may be chosen for clinical transfusion.

[Detection of panel-reactive antibody before and after renal transplantation: analysis of 641 cases].

OBJECTIVE: To explore the significance of the panel-reactive antibody (PRA) detection in renal transplantation. METHODS: Enzyme-linked immunosorbent assay (ELISA) was used to measure the PRA levels in 641 patients with renal transplantation, of whom 570 were examined preoperatively while 71 postoperatively. RESULTS: Of the 570 cases examined preoperatively for PRA levels, 490 cases were negative of PRA in which acute rejection occurred in 35 cases (7.14%) after the transplantation, while in the 68 cases with slightly positive PRA as detected preoperatively, acute rejection occurred in 36 cases (52.9%). Among the 12 cases with positive PRA assay both before and after the operation, acute rejection took place in 10 cases (83.3%). As for the 71 patients receiving postoperative PRA detection, 59 were PRA-negative, among whom acute rejection occurred in only 3 cases (5.08%), while 7 (58.3%) out of the 12 PRA-positive experienced episodes of acute rejection. CONCLUSION: PRA-positive recipients of the renal transplantation have higher risks of acute rejection of the graft, and PRA detection both before and after the operation may be of great importance.

[Observation on gene polymorphism of Rh blood group in Chinese Han nationality].

To observe the gene polymorphism of Rh blood group in unrelated random individuals and families for Chinese Han nationality, polymerase chain reaction-sequence specific primer (PCR-SSP) was used to amplify the Rh C/E gene, RhD gene, exons, intron 2 and 10, insert and Rh Box in 160 blood samples of RhD positive unrelated individuals and 71 samples of RhD negative unrelated individuals and 7 samples of families whose probands were RhD-negative. The results showed that RhD genes of RhD-negative individuals with C antigens were polymorphism, three forms were found for D exon including intact, partial deletion and complete deletion exons. Insert fragments and Rh Box were found in most cases of families whose probands were RhD-negative and its inheritance accorded with the Mendel's Law, and it did not affect the expression of RhD gene. "Normal" RhD exon 4 amplifying product was not found in all of the samples. It was concluded that gene structure of the RhD-negative in Chinese was polymorphism, intact, partial deletion and complete deletion exons were found in the individuals with C antigen and probably existed specific D (nf) Ce haplotype. The function of insert was uncertain. The Rh gene sequences of Chinese Han nationality are different from those of Caucasian and the Rh gene library based on Han nationality should be established.

[Comparative analysis of serologic typing and HLA-II typing by micro-PCR-SSP].

OBJECTIVE: To evaluate the accuracy of polymerase chain reaction with sequence specific primers (PCR-SSP) in HLA-II genotyping and analyze the causes of the errors occurring during the genotyping. METHOD: Blood samples were obtained form patients with chronic renal insufficiency, leukemia or thalassemia and also from normal subjects. HLA-DR and -DQ genotyping of the sera from the 110 subjects was performed using micro-PCR-SSP and comparison was made with the results obtained from monoclonal antibody serologic typing. RESULT: Of the 110 samples detected by micro-PCR-SSP, 396 alleles of HLA-DR were identified in 99 cases and 22 of HLA-DQ in 11 cases, and 10% of the subjects were identified as homozygote individuals. Examination by both of the 2 methods in 67 cases indicated high rates of missed diagnoses and misdiagnoses by serologic typing with the diagnostic discrepancy as high as 38.81% and 50.75% for HLA-DR and -DQ respectively. The antigens DR 15/16, 11/12, 13/14, 8 or 12; DQ 5/6, 8/9 were among those that frequently gave rise to errors or confusion. CONCLUSION: Micro-PCR-SSP method can accurately detect the alleles of HLA-II antigens that are easy to be missed or mistaken by serological typing method.

[Research of Typing for HLA-A, -B on Cord Blood Lymphocytes]

Serological typing for HLA-A, -B has been used for a long time. Recently with the developing of molecular biology technologies, HLA-A, -B typing is now turning to genotyping methods. In our study, the capacity of PCR-SSP in solving problems in HLA-A, -B typing with serological methes was evaluated. With this aim the serological method was compared with PCR-SSP in 102 cord blood samples, and the results showed that 18.6% of 102 cord blood samples can't give a satisfactory detection, for 14 samples, give discrepant results with the 2 methods. It is mainly due to weak expression of HLA class I cord blood lymphocytes and the cross reaction of some antigens. About B 15 group, the further study was made, it was found that most of the B 15 splits is wrongly disassigned, especially among the B62-B75, B75/*1511(+)-B75/*1511(-), B46-*1511 antigens. It was concluded that DNA typing is more preferable than serological typing, about B 15 group, the subtyping or high resolution typing can be fulfilled at first in China.