Biomedical subjects

Minyan Qiu

Publications and source records attributed to Minyan Qiu.

4 recordsLinked to original sources

PubMed2006

Screening genetically modified organisms using multiplex-PCR coupled with oligonucleotide microarray.

In this research, we developed a multiplex polymerase chain reaction (multiplex-PCR) coupled with a DNA microarray system simultaneously aiming at many targets in a consecutive reaction to detect a genetically modified organism (GMO). There are a total of 20 probes for detecting a GMO in a DNA microarray which can be classified into three categories according to their purpose: the first for screening GMO from un-transgenic plants based on the common elements such as promoter, reporter and terminator genes; the second for specific gene confirmation based on the target gene sequences such as herbicide-resistance or insect-resistance genes; the third for species-specific genes which the sequences are unique for different plant species. To ensure the reliability of this method, different kinds of positive and negative controls were used in DNA microarray. Commercial GM soybean, maize, rapeseed and cotton were identified by means of this method and further confirmed by PCR analysis and sequencing. The results indicate that this method discriminates between the GMOs very quickly and in a cost-saving and more time efficient way. It can detect more than 95% of currently commercial GMO plants and the limits of detection are 0.5% for soybean and 1% for maize. This method is proved to be a new method for routine analysis of GMOs.

Animals↗

PubMed2005

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 microM), 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 microM 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.

Nucleic Acid Heteroduplexes↗

PubMed2004

Systematic comparison of the fidelity of aRNA, mRNA and T-RNA on gene expression profiling using cDNA microarray.

In cDNA microarray technology, there are three main reverse transcription based RNA labeling methods, using total RNA (T-RNA), mRNA, and amplified antisense RNA (aRNA), respectively. However, despite the common use of the three types of RNAs, limited data are available regarding their differences and concordances. In this report, we compared the three methods through two sets of self-comparison experiments using the same RNA sample in all cases. Within each method, duplicate hybridizations are highly reproducible with low biases, which are randomly produced. When combining different RNAs within a single array, correlation coefficients between the two channels are rather low, while the discrepancies are persistent. Furthermore, the fidelity of aRNA and mRNA microarrays in the expression profile study shows no significant difference with standard T-RNA based labeling methods. These results suggest that some RNA abundance are selectively changed during aRNA amplification/mRNA purification processes, but it will not affect the gene expression ratio of the two samples if the same type RNA are used. Therefore all three types of RNAs can be used in expression profiling analysis as long as the test and reference samples are generated by identical method within single study.

Carcinoma, Hepatocellular↗

PubMed2002

Discovery and analysis of hepatocellular carcinoma genes using cDNA microarrays.

PURPOSE: Microarray analysis on a genomic scale was used to profile changes in gene expression accompanying hepatocellular carcinoma. METHODS: Gene expression profiles of liver tissues from twelve hepatocellular carcinoma samples relative to the gene expression profile of the normal liver tissue were analyzed using 4096 chips and 12800 chips. The results of microarray experiments were verified by the Northern blot technique. RESULTS: A group of 1,820 genes with altered expression were identified in more than 50% of the patients examined. This highly concordant expression profile included human genes encoding proteins involved in the function of peroxisomes, serum control, polycyclic aromatic hydrocarbon carcinogenesis, cell growth and differentiation, metastasis, the function of the immune system, apoptosis, and remodeling of the cytoskeleton. CONCLUSIONS: The newly identified genes afford a quantitative view of the changes that accompany liver cancer at the genomic level, enable deeper insights into the molecular basis of disease, and provide an extensive list of potential early-onset molecular markers for improved diagnosis.

Adult↗