Each known chromosome 21 gene and predicted open reading frame (ORF), identified using MWG-Biotech's non-redundant proprietary database, is represented once in the array by a 40-nucleotide-long oligonucleotide. A total of 498 chromosome 21-specific oligonucleotides are on the array, none of which contains any stretch longer than 15 bases that is homologous to any other sequence in the genome. These oligonucleotides are produced in-house and are quality controlled by MALDI-TOF mass spectrometry. Investigators can purchase the chip alone or as part of a package that includes coursework, an array scanner, and data-analysis software.
According to Horst Donner, head of development for microarrays at MWG-Biotech, both the sequence-specificity of the oligonucleotides on the array, and the automation of the company's array production, increase the sensitivity and reproducibility of these arrays. However, he indicated that the company will not release data on the sensitivity of its arrays until it can develop a quantitative ...
