Molecular diagnostics assays

Feigenbaum A, Moore R, Clarke J, Hewson S, Chitayat D, Ray PN, Stockley TL. Canavan disease carrier frequency determination in the Ashkenazi Jewish population and development of a novel molecular diagnostic assay. Am J Med Genet 2004 124A 142-147. 

This assay was used for the detection of three genes which are associated with MRSA and three different SERRS labels namely EAM, HEX, and TAMRA were used to identify these sequences. Using this approach it was possible to detect not only the exact complement DNA but also PCR product. It was also possible to detect every possible combination of the three sequences, present or absent, within a mixture demonstrating the multiplexing potential of SERRS for use in homogeneous molecular diagnostics assay. 

Nanosphere aimounces FDA clearance of second molecular diagnostics assay. Available at http //ir.nanosphere.us/phoenix.zhtml c=214748 p=irol-newsArticle ID=1075929 highlight=. Accessed March 23, 2008. 

One of the primary responsibilities of the director of a molecular genetics testing center is to make certain that appropriate controls are devised for and run with each diagnostic assay. An elaborate system of checks exists in most genotyping laboratories in order to make certain that each released result meets a written QC standard. In the absence of QA/QC, patients, physicians, and researchers cannot rely upon the genotypes being produced. 

Recently, introduction of DNA analogous detection systems such as the use of peptide nucleic acid (PNA) technology has attracted considerable attention [10]. The PNAs are synthetic analogues of DNA that hybridise with complementary DNAs or RNAs with high affinity and specificity, essentially because of an uncharged and flexible polyamide backbone. The unique physico-chemical properties of PNAs have led to the development of a variety of research and diagnostic assays where these are used as molecular hybridisation probes [11]. 

Munro, N.J., Snow, K., Kant, J.A., Landers, J.P., Molecular diagnostics on micro-fabricated electrophoretic devices From slab gel- to capillary- to microchip-based assays for T- and B-cell lymphoproliferative disorders. Clin. Chem. 1999, 45(11), 1906-1917. 

An advantage of the ASO method is that it can be used to simultaneously test samples for several different mutations by the use of multiple probes bound to a solid matrix. In practice, the success of this method relies on precisely establishing conditions for optimal oligonucleotide hybridization in order to ensure specific probe hybridization, and so multiplex ASO assays can be difficult to develop. Molecular diagnostic kits for use in genetic disorders based on ASO methods are available (14). 

Primer extension assays are very sensitive for mutation detection and may be advantageous for large-scale testing with some modifications to the basic protocol. Primer extension assays have been designed to use fluorescent dye labeled nucleotides to eliminate the need for radioactivity and may also be adaptable to use on solid supports (22). For molecular diagnostics purposes, there are also commercially available kits and protocols for diagnostic applications (23). 

Munro NJ, Snow K, Kant J, Landers JP. Molecular diagnostics on microfabricated electrophoretic devices Translating slab gel-based T- and B-cell lymphoprohf-erative disorder assays from the capillary to the microchip. Clin Chem 1999 45 1906-17. 

Proficiency testing for molecular diagnostics laboratories remains a challenge because adequate proficiency testing programs are unavailable to cover the wide variety of molecular assays offered by a number of laboratories. The CAP offers the only proficiency program accredited for molecu-... 

While the fierce competition from NGS at the high end of throughput and from PCR-based techniques at the low end has hindered the DNA microarrays in the molecular diagnostic market however, microarrays still have advantages over these competing techniques. The price of NGS assays, although not prohibitive anymore, are still more expensive than the ones offered by... 

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