Detection of tomato yellow leaf curl virus by loop-mediated isothermal amplification reaction

The genomic DNA molecule of tomato yellow leaf curl virus (TYLCV), a whitefly-transmitted geminivirus, was amplified from total DNA extracts of TYLCV-infected tomato (Lycopersicon esculentum) by the use of loop-mediated isothermal amplification (LAMP). The procedure was also used to amplify TYLCV DNA from total DNA extracts of individual whiteflies (Bemisia tabaci) that had fed on TYLCV-infected plants. One of the characteristics of the LAMP method is its ability to synthesize an extremely large amount of DNA. Accordingly, a large amount of by-product, pyrophosphate ion, is produced yielding a white precipitate of magnesium pyrophosphate in the reaction mixture. The presence or absence of this white precipitate allows easy detection of amplification of TYLCV genomic DNA without gel electrophoresis. (C) 2003 Elsevier B.V. All rights reserved.