Methylation-Sensitive Loop-Mediated Isothermal Amplification (LAMP): Nucleic Acid Methylation Detection through LAMP with Mobile Fluorescence Readout
Jacob Amos Hambalek, Janay Elise Kong, Calvin Brown, Hector E. Muñoz, Thomas Horn, Michael Bogumil, Eleni Quick, Aydogan Özcan, Dino Di Carlo
Abstract
The emergence of epigenetic gene regulation and its role in disease have motivated a growing field of epigenetic diagnostics for risk assessment and screening. In particular, irregular cytosine DNA base methylation has been implicated in several diseases, yet the methods for detecting these epigenetic marks are limited to lengthy protocols requiring bulky and costly equipment. We demonstrate a simple workflow for detecting methylated CpG dinucleotides in synthetic and genomic DNA samples using methylation-sensitive restriction enzyme digestion followed by loop-mediated isothermal amplification. We additionally demonstrate a cost-effective mobile fluorescence reader comprising a light-emitting diode bundle, a mirror, and optical fibers to transduce fluorescence signals associated with DNA amplification. The workflow can be performed in approximately 1 h, requiring only a simple heat source, and can therefore provide a foundation for distributable point-of-care testing of DNA methylation levels.