The invention relates to the technical field of biological detection, and discloses a method for double-ring detection of
lung cancer L858R
mutation based on
CRISPR / Cas9 and
DNA, and the method comprises the following steps: enriching circulating
tumor cells CTC from a blood sample; extracting
genomic DNA (deoxyribonucleic acid) of the enriched CTC; carrying out amplification on the
DNA fragment containing the L858R
mutation by adopting
recombinase polymerase amplification RPA (
recombinase polymerase amplification); the amplified
DNA fragment is hybridized with a recognition ring in
a DNA double-ring structure,
a DNA double ring is composed of the recognition ring and a report ring, and a part of region of the recognition ring is hybridized with a corresponding fragment of the report ring to form a staggered double-chain region; when L858R
mutation exists, the mutated DNA and a recognition ring are hybridized to activate a
CRISPR / Cas9
system, and under the guidance of sgRNA, Cas9 cuts
hybrid double strands and releases a report ring; carrying out rolling circle amplification RCA under the action of
DNA polymerase by taking the released report ring as a template; a fluorescent probe is used for detecting an RCA amplification product, and whether L858R mutation exists or not is judged according to a
fluorescence signal. The
CRISPR / Cas9
system is combined with
a DNA double-ring structure, so that the ultra-sensitive and
specific detection on the
lung cancer L858R mutation is realized.