Detection of loop-mediated isothermal amplification reaction by turbidity derived from magnesium pyrophosphate formation

The loop-mediated isothermal amplification (LAMP) is a novel nucleic acid a mplification method that uses only one type of enzyme. One of the character istics of the LAMP method is its ability to synthesize extremely large amou nt of DNA. Accordingly, a large amount of by-product, pyrophosphate ion, is produced, yielding white precipitate of magnesium pyrophosphate in the rea ction mixture. Judging the presence or absence of this white precipitate al lows easy distinction of whether nucleic acid was amplified by the LAMP met hod. Since an increase in the turbidity of the reaction mixture according t o the production of precipitate correlates with the amount of DNA synthesiz ed, real-time monitoring of the LAMP reaction was achieved by real-time mea surement of turbidity. (C) 2001 Academic Press.