Multiplex allele-specific diagnostic assay

Fig. 4. Illustration of the multiplex allele specific diagnostic assay. At the top of the panel, radioactive ohgonucleotide probes (indicated by stars) are selected by hybridization to amphcons from patient samples affixed to membrane filters. When a putative mutation-bearing allele hybridizes to a radioactive probe, it can be eluted from the filter and subjected to sequencing using chemical or radioactive dideoxy-terminator methods. This permits unequivocal identification of a large number of mutations at a high throughput.

There have been improvements to the ASO assay, specifically by development of a multiplex allele-specific diagnostic assay (MASDA) in which the ASO technique is adapted to a solid support and multiple regions are probed simultaneously. This has been achieved by altering probe... 

Figure 40-10 Methylation-specific PCR assay for the diagnosis of PWS and AS, Extracted DNA is treated with sodium bisulfate before amplification using multiplex PCR and oligonucleotide primers specific for modified DNA. Normal individuals show amplicons representing their methylated maternal allele and amplicons from their unmethylated paternal allele. PWS patients show only the maternal allele and AS patients show only the paternal allele. Results observed following PCR amplification and gel electrophoresis of patients referred for PWS and AS testing. Patient DNA with patterns diagnostic of AS (/ones / and 5),...

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