▎ 摘　　要

NOVELTY - Kit comprises nucleotide chains chosen from A1 chain, A2 chain, A3 chain, AP chain and fluorescent chain, a magnetic bead mixture, phosphate-buffered saline (PBS) buffer, bovine serum albumin (BSA) buffer and Cutsmart(RTM: Optimal buffer) buffer. USE - The kit is useful for detecting miRNA Let-7a based on assistance of magnetic bead and graphene oxide (claimed). ADVANTAGE - The kit achieves high sensitivity and high selectivity detection of target genes. DETAILED DESCRIPTION - Kit comprises nucleotide chains chosen from A1 chain, A2 chain, A3 chain, AP chain and fluorescent chain, a magnetic bead mixture, phosphate-buffered saline (PBS) buffer, bovine serum albumin (BSA) buffer and Cutsmart (RTM: Optimal buffer) buffer. The A1 chain has a base pair sequence: 5'-gtctccaactgtgctgagg-3' (SEQ ID NO: Not defined). The A2 chain has a base pair sequence: 5'-agtaggttgtatagtttccctagtagttaac-3' (SEQ ID NO: Not defined). The A3 chain has a 48 base pair sequence (SEQ ID NO: Not defined) fully defined in the specification. The AP chain has a 37 base pair sequence (SEQ ID NO: Not defined) fully defined in the specification. The fluorescent chain has a base pair sequence: 5'-tagcgttaactgcatgg-3' (SEQ ID NO: Not defined), where 3' end is modified with a carboxyfluorescein (FAM) group. An INDEPENDENT CLAIM is included for use of the kit for detecting micro RNA (miRNA) lethal-7a (Let-7a) for purpose of non-disease diagnosis by (i) preparing A1 chain solution, A2 chain solution and A3 chain solution, and mixing and incubating to obtain a triple-strand complex substrate solution, (ii) adding PBS buffer and magnetic bead mixture to the triple-strand complex substrate solution, mixing well, and incubating under shaking conditions until the reaction is complete, (iii) centrifuging the reaction solution, separating the magnetic beads, taking out the reaction solution, adding BSA buffer solution into the reaction tube containing the magnetic beads, and incubating under shaking conditions until the reaction is complete, (iv) centrifuging the solution, separating the magnetic beads, taking out the reaction solution, adding PBS buffer, test solution and AP chain solution to the reaction tube containing magnetic beads in sequence, shaking evenly and incubating until the reaction is complete, (v) mixing graphene oxide solution, fluorescent chain solution and Cutsmart (RTM: Optimal buffer) buffer, shaking and incubating until fully combined, adding the reaction solution that removes the magnetic beads in step (iv), shaking and incubating, and detecting peak value of the fluorescence intensity, and (vi) substituting peak fluorescence intensity into the standard curve to calculate the concentration of miRNA Let-7a.