The therascreen EGFR RGQ PCR Kit version 2 enables detection of exon 19 deletions, L858R, L861Q, G719X, S768I, exon 20 insertions, and the resistance mutation T790M in the EGFR gene. The EGFR gene encodes the epidermal growth factor receptor (EGFR) protein. Mutations in the tyrosine kinase domain of the EGFR gene can enable tumor growth and progression. EGFR mutations are found in approximately 10% of non-small cell lung cancer incidences in the US and 35% in East Asia.
The therascreen EGFR RGQ PCR Kit version 2 enables detection of 29 somatic mutations in the EGFR gene including:
- 19 deletions in exon 19
- 3 insertions in exon 20
The kitutilizes two technologies — ARMS (Amplification Refractory Mutation System) and Scorpions — for detection of mutations using real-time PCR on the Rotor-Gene Q HRM 5plex instrument.
Allele- or mutation-specific amplification is achieved by ARMS. Taq DNA polymerase is effective at distinguishing between a match and a mismatch at the 3' end of a PCR primer. Specific mutated sequences are selectively amplified, even in samples where the majority of the sequences do not carry the mutation. When the primer is fully matched, the amplification proceeds with full efficiency. When the 3' base is mismatched, only low-level background amplification occurs.
Detection of amplification is performed using Scorpions. Scorpions are bifunctional molecules containing a PCR primer covalently linked to a probe. The fluorophore in this probe interacts with a quencher, also incorporated into the probe, that reduces fluorescence. When the probe binds to the amplicon during PCR, the fluorophore and quencher become separated. This leads to an increase in fluorescence from the reaction tube.