Store 18S Primer Pair and 18S Competimers at –20°C. Store Control Template RNA below –70°C. Store Nuclease-free water at any temperature.
The Ambion QuantumRNA™ 18S Internal Standard with Competimer™ technology uses specially modified Competimers of the same sequence as the normal 18S primers that cannot be extended. By adjusting the ratio of 18S Competimers to normal 18S mRNA primers, the signal for 18S mRNA can be attenuated to the level of very rare messages. They are used for quantitative end-point RT-PCR and include sufficient reagents for 100 reactions. Because of its invariant expression across tissues and treatments, 18S ribosomal RNA is an ideal internal control for quantitative RNA analysis. The Classic 18S Internal Standards contain the same primers/Competimers that were part of the original QuantumRNA 18S Internal Standards Module. They produce a 489 bp PCR product.
The QuantumRNA Classic II 18S Internal Standard (Cat. No. AM1717) produce a 324 bp PCR product, and the QuantumRNA Universal 18S Internal Standard (Cat. No. AM1718) function across the broadest range of eukaryotes, including animals, plants, and many protozoa and produce a 315 bp PCR product.