Gene probes hybridization

Figure 4. Simultaneous detection of HIV and Hepcidin (HEPC) SERS gene probe hybridizations.

Detection of Specific Sequences by Gene Probe Hybridization... 

Unlike other methods currently employed for quantitative transcript measurements, including cDNA microarrays and real-time RT-PCR, competitive RT-PCR is amenable to quality control, which is critical for clinical diagnostic and pharmaceutical industry applications. Furthermore, microarray approaches are limited to generating snap-shot like profiles, but they do not control for differences in hybridization efficiencies of different gene probes with their corresponding cDNAs. That is, cross comparisons are relative and not absolute. Real-time PCR has gained acceptance recently largely due to the reduced cost associated... 

Wodicka et al. (1997) created such an array for measuring yeasf gene expression based upon 25-mer oligonucleotides covering 6200 ORFs. Each ORF was represented by 20 PM and 20 MM probes. Why so many probes Simply put, not all probes hybridize in a predictable manner. Averaging across a number of probes improves the outcome. Thus, the yeast expression chip comprised over 65,000 probe features and required a set of four chip subarrays. 

Fig. 30. Detection of mRNA on a membrane or in situ with labeled gene probes. A Detection of mRNA with a fluorescein-labeled single stranded nucleic acid probe, using POD-conjugated anti-fluorescein antibody. B Use of two gene probes labeled with different molecules (fluorescein and digoxigenin) and detected with specific antibodies, both coupled to AP and using two substrates, leading to differently colored products. This in situ hybridization scheme allows the simultaneous detection of two mRNA species in a tissue or cell preparation. C Amplification systems involving more than one antibody can be used to increase specificity and signal intensity.

Labeled gene probes can also be used to detect specific genes or mRNA in tissue sections or in chromosome spreads. This technique is known as in situ hybridization. The detection of specific genes or gene... 

Oligonucleotide probe hybridizes with a DNA fragment from the gene for the p-chain of Hb S. 

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