Real-time loop-mediated isothermal DNA amplification in compact disc micro-reactors

An integrated device composed of micro-reactors embedded onto compact discs is proposed for real-time targeted DNA determination. The method principle is based on in-disc loop-mediated isothermal amplification (iD-LAMP) and quantitative optical read-out by a disc drive. In the presence of a target, the turbidimetric or colorimetric properties of reaction solution change, and the transmitted intensity of the disc drive laser modifies according to reaction yield. Monitoring real-time curves allowed the quantitative determination of DNA template amounts. The best amplification/detection results were obtained with micro-reactors (2mm diameter and 1.1mm in depth) drilled on a digital video disc (DVD) and detection based on the colorimetric mode. As proof-of-concept, the assay was applied to detect pathogenic bacteria Salmonella spp. and to identify bovine meat in food samples. Ninety-six samples were simultaneously analysed in 15min, with high selectivity and sensitivity (5CFU/mL and 10µg/g for bacteria and meat, respectively). The in-disc results were comparable to those obtained by conventional LAMP or qPCR approaches. The developed device allows low sample and reagent consumption (3µL of reaction), portability, ease-of-use, and rapid low-cost high-throughput analyses. This research has been funded through projects FEDER-CTQ/2013/45875-R (MINECO) and Prometeo II/2014/040 (GVA). The Spanish Ministry of Education and Science provided S.S.F. with a grant AP2009-4518 for her PhD studies. Santiago Felipe, S.; Tortajada-Genaro, LA.; Carrascosa Rubio, J.; Puchades, R.; Maquieira Catala, Á. (2016). Real-time loop-mediated isothermal DNA amplification in compact disc micro-reactors. Biosensors and Bioelectronics. 79:300-306. https://doi.org/10.1016/j.bios.2015.12.045