Mutation Detection

Because of the cost of the direct sequencing techniques described above,[1,2] many mutation detection procedures have been developed. The most important criteria for an efficient mutation screening technique is the detection of new mutations within a gene. Several methods have been developed to screen for sequence changes in either cellular RNA or genomic DNA, including denaturing gradient gel electrophoresis (DGGE),[3] chemical cleavage of mismatch (CCM),[4] single-stranded conformation polymorphism (SSCP),[5] heteroduplex analysis (HA),[6] conformation sensitive gel electrophoresis (CSGE),[7] and denaturing high-performance liquid chromatography (DHPLC).[8] These methods detect all sequence changes such as nonsense, frameshift, splice site, and missense mutations as well as polymorphisms, whereas the protein truncation test (PTT)[9] screens specifically for truncating mutations. The detection efficiency of these different methods varies significantly depending on the size of the template screened. Single-stranded conformation polymorphism has been one of the most popular screening procedures used over the last decade because of its simplicity along with a sensitivity of >95% for fragments of approximately 150 bp. However, this sensitivity decreases to <5% for fragments of around 600 bp.[10] Conformation sensitive gel electrophoresis is also technically simple and has a sensitivity of 90-100 % for fragments of up to 450 bp.[11] Denaturing gradient gel electrophoresis requires much optimization for each fragment screened, but will yield a sensitivity of ~ 99% for fragments of up to 500 bp.[12] Chemical cleavage of mismatch has a sensitivity of between 95% and 100% for fragments >1.5 kb in size[13] and is perfect for screening larger fragments while still achieving a high sensitivity of detection.

Getting Started With Dumbbells

Getting Started With Dumbbells

The use of dumbbells gives you a much more comprehensive strengthening effect because the workout engages your stabilizer muscles, in addition to the muscle you may be pin-pointing. Without all of the belts and artificial stabilizers of a machine, you also engage your core muscles, which are your body's natural stabilizers.

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