For a general overview of Pyrosequencing technology, please visit our Pyrosequencing resource center
The RAS Extension Pyro Kit consists of 8 assays covering the different regions of interest (see Figure 1. Assays of the RAS Extension Pyro Kit and Figure 2. Pyrogram trace obtained after analysis of a sample with a wild-type genotype with the KRAS 146 assay.). The regions are amplified separately by PCR and sequenced through the defined region. Sequences surrounding the defined positions serve as normalization and reference peaks for quantification and quality assessment of the analysis.
After PCR using primers targeting the different codons, the amplicons are immobilized on Streptavidin Sepharose High Performance beads. Single-stranded DNA is prepared, and the corresponding sequencing primers anneal to the DNA. The samples are then analyzed on the PyroMark Q24 System using a run setup file and a run file. The RAS Extension Plug-in Report should be used to analyze the run. This report ensures that the correct limit of detection (LOD) values are used and different sequences to analyze are automatically used to detect all mutations (see Figure 3. RAS Extension Plug-In Report menu and Figure 4. RAS Extension Plug-In Report). However, the run can also be analyzed using the analysis tool integral to the PyroMark Q24 System. The "Sequence to Analyze" can be then adjusted for detection of rare mutations after the run.