Analysis of the factors affecting the accuracy of detection for single base alterations by oligonucleotide microarray

The oligonucleotide microarray, a high-throughput polymorphism detection technology, holds great promise for the characterization of complex genetic variance. To achieve greater sensitivity and specificity for it to be an effective platform technology we present results and discuss some of the factors influencing signal intensities and single-mismatch discrimination in array-based mutation/SNP detection. Probes with a series of concentrations were spotted onto the slide in order to find the optimal concentration with the identifiable satisfying signals and the stable ratios between matched and mismatched probes. It was found that under our experimental conditions, when the initial probe concentration is higher than the maximum immobilization capability of the slide (7.5 micrometer), the hybridization signal will be saturated and the ratio between matched and mismatched probes will be more stable than at a lower probe concentration. Considering the cost of probes and the systematic stability, a constant spotting concentration of 10 micrometer was selected. The stability of different types of mismatched oligo-DNA duplexes on the glass surface was also confirmed. The results show that the order of stability of mismatched oligo-DNA duplexes on a glass surface is in general agreement with previous reports conducted using liquid and polyacrylamide gel pads. This suggests that the influence of the mismatched base pair on the stability of the duplex in a solid hybridization system is similar to that in the solution hybridization environment.

Microarray DNA Chip in Analyzing the Association Between HLA,DRB and Advanced Hepatosplenic Schistosomiasis / 中国寄生虫学与寄生虫病杂志

Objective To explore possible associations between host polymorphism of HLA classⅡgenotypes and advanced hepatosplenic schistosomiasis japonica.Methods 45 advanced schistosomiasis patients(experimental group) and 44 age,and sex,matched patients with chronic schistosomiasis(control group) from the same area were investigated for their HLA class II gene DRB genotypes by genotyping the alleles using microarray DNA chip.The correlation of allele frequencies to advanced hepatosplenic schistosomiasis was compared for the two groups.Results HLA,DRB1*04x exhibited markedly higher frequency in advanced patients than that in control group(P