Application of Molecular Diagnostic Techniques for Viral Testing

Cobo, Fernando

A DNA array (or DNA chip) is a collection of spots attached to a solid support where each spot contains one or more single-stranded DNA oligonucleotide fragment [26] . High density arrays, that permit attaching hundred or thousands of oligonucleotides, are referred to as microarrays. A labeled amplification product is hybridized to the probes, and hybridization signals are mapped to several positions within the array. The pattern of hybridization can identify the sequence of PCR, if the number of probes is sufficiently large. The results of hybridization between the bound probe and labeled sequences in the sample applied and tested are revealed by scanning or imaging the array surface. Confocal microscopy is used to scan the chip, detecting fluorescent signals that reveal hybridization at precise locations on the chip. As many DNA sequences can be present on a slide, it is possible for microarray analysis to test for multiple viruses simultaneously.