The therascreen EGFR Plasma RGQ PCR Kit enables detection of clinically proven somatic mutations in the EGFR gene on cfDNA extracted from plasma of NSCLC patients. 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 NSCLC incidence in the US and 35% in East Asia. Additionally, EGFR mutations are found in 6% of brain tumors.
The therascreen EGFR Plasma RGQ PCR Kit is a ready-to-use kit for the detection of mutations in the EGFR cancer-related gene using polymerase chain reaction (PCR) including:
- Deletions in exon 19
- T790M
- L858R
The methods used are highly selective and, depending on the total amount of cfDNA present, enable detection of a low percentage of mutant in a background of wild-type cfDNA.
The kitutilizes two technologies — ARMS (Amplification Refractory Mutation System) and Scorpions — for detection of mutations using real-time PCR on the Rotor-Gene Q MDx instrument.
ARMS
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.
Scorpions
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.