The invention discloses a preparation method and an application for a dual-
fluorescence reporting system for detecting a micro-
RNA (ribonucleic acid) function, wherein the preparation method comprises the following preparation steps of: A, obtaining a
mCherry gene sequence via a PCR (
polymerase chain reaction) amplification, inserting a rho EGFP-C1 carrier to replace the EGFP (
enhanced green fluorescent protein) sequence of the
mCherry gene sequence, and constructing a carrier rho
mCherry-C1; B, using a RNAi-Ready rho SIREN-RetroQ
plasmid as a template, obtaining a human U6
promoter gene via a PCR amplification, and inserting the carrier rho mCherry-C1 to obtain a
plasmid rho hU6-mCherry-C1; and C, obtaining a
gene sequence carried with a CMV (cytomegalovirus)
promoter and an EGFP expression dialog sequence in an interval of 358 to 1944 on a
plasmid rho Adtrack-CMV, and inserting the sequence in the plasmid rho hU6-mCherry-C1 to obtain a plasmid rho MGhU6. The plasmid rho MGhU6 is a dual-
fluorescence reporting system simultaneously containing a mCherry reporting gene, an internal reference EGFP, a micro-
RNA and the target sequence
insertion site thereof. The
reporting system can be used for detecting the inhibition function of the micro-
RNA to the target sequence expression. The detection method is easy, as well as simple and convenient in operation; and a function detection for the micro-RNA can be realized by transfecting one plasmid only. The
system also can be used for visually detecting the inhibition function of a micro-RNA in a single
living cell to the target thereof by the aid of
fluorescence microscopic imaging.