RESUMO
cDNA microarray-based CGH (Microarray-CGH) is a useful technique for detecting genomic aberrations with a high resolution. However, the criteria for determining a genomic alteration have not been determined. We evaluated the genome-wide measurement of copy number of each gene in normal gastric and placenta tissues with both sex-matched, direct and sex-mismatched, indirect designs using 17K cDNA microarray. The results revealed the range of genomic copy number of normal tissues to be +/-0.3 of the log(2) ratio (gain >0.3, loss <-0.3) in the autosomal genes with direct and indirect designs. The copy number at a gene level from the X chromosomal genes using the direct and indirect sex-mismatched designs was +/-0.68 of the log(2) ratio (amplification >0.68, deletion <-0.68). In summary, the suggested method can be used as a guideline for analysis of genomic aberration using a Microarray-CGH in both direct and indirect designs.
Assuntos
Hibridização de Ácido Nucleico/métodos , Análise de Sequência com Séries de Oligonucleotídeos , Cromossomos Humanos/genética , Feminino , Genoma Humano/genética , Humanos , Hibridização in Situ Fluorescente , MasculinoRESUMO
DNA microarray technology has become an essential part of biological research. It enables the genome-scale analysis of gene expression in various types of model systems. Manufacturing high quality cDNA microarrays of microdeposition type depends on some key factors including a printing device, spotting pins, glass slides, spotting solution, and humidity during spotting. UsingEthe Microgrid II TAS model printing device, this study defined the optimal conditions for producing high density, high quality cDNA microarrays with the least amount of cDNA product. It was observed that aminosilane-modified slides were superior to other types of surface modified-slides. A humidity of 30+/-3% in a closed environment and the overnight drying of the spotted slides gave the best conditions for arraying. In addition, the cDNA dissolved in 30% DMSO gave the optimal conditions for spotting compared to the 1X ArrayIt, 3X SSC and 50% DMSO. Lastly, cDNA in the concentration range of 100-300 ng/ micro l was determined to be best for arraying and post-processing. Currently, the printing system in this study yields reproducible 9000 spots with a spot size 150 mm diameter, and a 200 nm spot spacing.