xMAP multiplex-detection of plant viruses

Current detection methods for plant pathogens are, in general, designed to detect one pathogen at the time. Multiplex detection of different plant pathogens in a single sample is an elegant way to improve efficiency, and lower costs as a result. Multiplex detection not only decreases handling time but also reduces the amount of consumables and reagents needed. The Luminex xMAP technology provides a very quick and state of the art platform to utilize multiplex detection. This platform is designed to fit both serological and molecular methodologies The Luminex xMAP platform makes use of different colour-coded beads which are coated with specific antibodies or primers. When the beads are added to the sample, the specific coated beads will bind to their individual targets. After binding, the target is labelled by specific conjugated antibodies or probes which will give a fluorescent signal. The colour code of the bead in combination with the fluorescent signal identifies a unique combination. Currently beads are available in 500 different colour-codes, so (theoretically) up to 500 plant pathogens can be detected in one single sample. In serological applications, the Luminex xMAP technology is closely related to the generally used DAS-ELISA whereby the viruses and/or bacteria are now captured on the surface of an antibody conjugated xMAP beads. The standard 96 wells ELISA format is retained to comply with common laboratory practices and automation. In contrast to conventional ELISA which can take op to several days to complete a Luminex xMAP test can be performed in less than 2 hours without any compromise to specificity and sensitivity. The Luminex xMAP technology platform also offers an excellent multiplex platform for enzymatic and receptor-ligand assays as well as different nucleic acid detection test. Coating beads with specific tags or primers allows sensitive, quantitative and multiplex detection of for instance PCR products or SNPs. Multiplex Luminex tests for several combinations of plant viruses in different crops like potato, tomato and carnation are now operational. Their development and testing will be discussed.