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Objective To test and evaluate the JAK2 gene V617F mutation in patients with myeloproliferative tumors based on i-densy IS-5320 platform according to ISO15189 accreditation requirements.Methods Instrument performance verification.Selected from December 2014 to February 2017, 20 cases of JAK2 V617F mutation positive peripheral blood samples from Huashan Hospital of the Shanghai FuDan University Medical College and 20 cases of peripheral blood samples with negative JAK2V617F mutation.The Realtime PCR with TaqMan MGB probe was selected as the control method to verify and evaluate the accuracy of testing JAK 2 V617F mutation on i-densy IS-5320 platform.Whole blood samples were used to evaluate the reproducibility , cross-contamination and anti-interference ability of this platform.The ability of mutation load was verified by detecting mixtures of human erythnoleukemia cells and colorectal cancer cell HCT116 with 12 different proportions.Results I-densy IS-5320 platform and TaqMan MGB probe real-time fluorescence quantitative PCR show the same result .The within-run reproducibility and between-run reproducibility are both 100%.There is no observed contamination .High bilirubin and high triglyceride blood samples have no obvious interference on mutation detection .The mutation ratio with a load as low as 0.25%could be tested stably by i-densy IS-5320 platform.The detecting peak of melting curve can reflect the ratio of JAK2 V617F mutation to some extent.Conclusions I-densy IS-5320 can detect the mutation of JAK2 V617F gene in the whole blood directly.It has high sensitivity, accuracy and stability, and is easy to operate, and also can reflect the mutation load of JAK2 V617F, which could meet the clinical requirements for the detection of mutations.
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Objective To study the correlation between apolipoprotein E (APOE) genetic polymorphisms and sepsis in Chinese children.Methods The inpatients suffered with sepsis were enrolled as septic group and the healthy children from child health division were enrolled as control group.The study of APOE genotypes were carried out by polymerase chain reactions followed a high-resolution melting curve analysis.SPSS 16.0 statistical software was used for data analysis.Mann-Whitney U test was used to compare the age between the groups.Hardy-Weinberg equilibrium was tested using the Pearson x2-test.The x2-test was used to compare gender and the genotype distribution between the groups.The odd ratio (OR) was calculated together with its 95％ confidence interval (CI).Potential confounding effects of variables were corrected using a multivariate unconditional logistic regression model.All statistical tests were two-sided and P ＜ 0.05 indicates statistically significance.Results Among a total of 285 children collected from March 2011 to June 2012,there were 88 patients with sepsis and 197 healthy children.In the septic group,15 septic patients were complicated with central nervous system infection.Four apolipoprotein E genotypes were identified to be ε3/ε3,ε2/ε3,ε3/ε4,and ε2/ε4.The percentage of each genotype found in patients of the septic group and the control group was 64.4％ vs.73.1％ (ε3/ε3);16.8％ vs.10.7％ (ε2/ε3);18.8％ vs.14.7％ (ε3/ε4);0％ vs.1.5％ (ε2/ε4),respectively.The number of patients with the genotype ε3/ε3 among septic patients was significantly lower than that among the control individuals (P =0.047,1-β =0.334,OR =0.585,adjusted OR =0.559).The number of patients with the genotype ε3/ε3 among the septic patients with central nervous system infection was 33.3％,which was also significantly lower than that among the septic patients without CNS infection (67.1％).(P =0.014,1-β5 =0.685,OR =0.245,adjusted OR =0.275).Conclusions Apolipoprotein E genetic polymorphisms were associated with the occurrence of sepsis and central nervous system complications in children.The susceptibility of children with genotype ε3/ε3 to sepsis and central nerve system infection complications is significantly lower than that of children with other genotypes.
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Background: Early detection of multidrug‑resistant tuberculosis (MDR‑TB) is essential to prevent its transmission in the community and initiate effective anti‑TB treatment regimen. Materials and Methods: High‑resolution melting curve (HRM) analysis was evaluated for rapid detection of resistance conferring mutations in rpoB and katG genes. We screened 95 Mycobacterium tuberculosis clinical isolates including 20 rifampin resistant (RIF‑R), 21 isoniazid resistant (INH‑R) and 54 fully susceptible (S) isolates determined by proportion method of drug susceptibility testing. Nineteen M. tuberculosis isolates with known drug susceptibility genotypes were used as references for the assay validation. The nucleotide sequences of the target regions rpoB and katG genes were determined to investigate the frequency and type of mutations and to confirm HRM results. Results: HRM analysis of a 129‑bp fragment of rpoB allowed correct identification of 19 of the 20 phenotypically RIF‑R and all RIF‑S isolates. All INH‑S isolates generated wild‑type HRM curves and 18 out of 21 INH‑R isolates harboured any mutation in 109‑bp fragment of katG exhibited mutant type HRM curves. However, 1 RIF‑R and 3 INH‑R isolates were falsely identified as susceptible which were confirmed for having no mutation in their target regions by sequencing. The main mutations involved in RIF and INH resistance were found at codons rpoB531 (60% of RIF‑R isolates) and katG315 (85.7% of INH‑R isolates), respectively. Conclusion: HRM was found to be a reliable, rapid and low cost method to characterise drug susceptibility of clinical TB isolates in resource‑limited settings.
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Objective To establish a rapid genotyping method of for methicillin-resistant Staphylococcus aureus(MRSA) based on polymerase chain reaction(PCR)-high resolution melting (HRM ) curve analysis and staphylococcal protein A (SPA ) classifica-tion .Methods 71 strains of MRSA clinically isolated were collected as test strains .Gene sequencing and HRM curve analysis were employed to conduct SPA gene typing .Results According to gene sequencing method ,SPA gene of 71 strains of MRSA was divided into four types ,namely t570 ,t030 ,t002 and t588 .The most predominant type was t570 (74 .65% ) ,followed by t030 and t002(both 7 cases) .The result of SPA gene typing by HRM analysis were basically consistent with that by gene sequencing .Con-clusion PCR-HRM analysis is expected to become a fast ,efficient genotyping for MRSA SPA gene ,providing the basis for hospital infection control .
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Genomic DNA isolation in cotton is complicated because of the presence of secondary metabolites that are inhibitory to PCR amplification. We report here that radicle tips, but not other parts of cotton seedlings, yield high-quality DNA that is readily amenable for PCR. The radicle-tip-excised seedlings retain viability because of the formation of adventitious roots. We demonstrate the utility of this method in distinguishing homozygotes from heterozygotes in a cotton breeding population and in hybrid seed purity testing.
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Objective To evaluate the feasibility of detecting the mutation of IDH1 in glioma patients by high resolution melting(HRM) curve analysis.Methods The gene mutation of IDH1 was detected by HRM method in 9 surgical resection paraffin specimens of glioma,and the result was verified by gene sequencing.Results 6 cases of R132H(CGT ＞ CAT) mutation and 1 case of R132C(CGT ＞ TGT) mutation were found by HRM method.The resluts of direct gene sequencing were consistent with HRM method.Conclusion The HRM method in detecting IDH1 mutation is more efficient and convenient than direct sequencing.Moreover,it has advantages of low-cost and suitable for clinical test.