Differential display (DD) technique was developed 13 years ago as a systematic method for studying eukaryotic gene expression. The updated method utilizes a combination of three frequently used molecular biology techniques: reverse transcription (RT) of messenger ribonucleic acid [Pol (A)+ mRNA] followed by polymerase chain reaction (PCR) of the resulting complementary deoxyribonucleic acid (cDNA); polyacrylamide gel (PAG) electrophoresis; and cDNA cloning to visualize and compare gene expression patterns between two or more samples. Reverse transcription uses one of three individual one-base fluorescently labeled anchored oligo-dT primers to amplify the 3' terminal of the mRNA by PCR, instead of the original isotopic labeling method, in combination with one of the various 10-13 arbitrary (random) nucleotide primers. The resulting cDNAs are separated on a denaturing, and sometimes nondenaturing, PAG. A fluorescent scanner views the pattern of bands. The cDNA fragments of interest are retrieved from the gel, purified, reamplified, and either cloned or directly sequenced to identify the differently regulated genes. Finally, confirmation of the differential expression of resulting cDNAs can be carried out by a method such as Northern blotting, RNase protection, or quantitative real-time RT-PCR. Following confirmation, the cloned cDNA probes can be used either to screen a cDNA library for a full-length clone, or more easily to carryout rapid amplification of cDNA ends (5'-RACE).

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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