I

Competitor

Whenratio=l:l Target-Competitor

Fig. 3 Example of competitive RT-PCR assay. The assay was performed by the addition of four different dilutions of the specific RNA competitor (from 108 to 105 molecules) to the unknown sample, prior to the reverse transcriptase reaction (RT). Final quantitation was performed by evaluating competitor/target ratio, as described for DNA measurement.

technology. Because PCR procedures for gene amplification must be able to measure the increase of even a few gene copies, the exact amount of DNA in each sample must be determined more accurately than by spectrophotometry: measurement. For this reason, an accurate assay must include a first competitive PCR in which the absolute number of a single copy reference gene is evaluated. This allows the performance of a second competitive PCR in which all samples are measured for gene amplification starting from exactly the same number of DNA molecules.[2-4] An example of the measurement of c-erbB-2 oncogene amplification is reported in Fig. 2. This technique is highly sensitive and allows the measurement in isolated cells obtained by flow sorting,[12] or even in samples with degraded DNA, as in the case of archived samples.[1]

Competitive PCR for RNA measurements; assay procedure

The assay procedure for c-RT-PCR requires the use of an RNA competitor to be added before the reverse transcription according to the scheme reported in Fig. 3. The calculation of the results is the same as for DNA measurements.

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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