This new high-throughput method for genetic purity testing of maize is based on homogenization of single seed kernels in a standard 96-well microtiter plate, followed by isoelectric focussing (IEF) of the homogenate and staining for the isoenzyme malate dehydrogenase (MDH).
The extraction of MDH is done with a special extraction buffer. IEF of the homogenates is done using the Sinus MDH Gel Kit comprising highly reproducible rehydrated gels. These non-toxic acrylamide gels with in-gel wells enable quick and easy sample loading using a 12-channel multipipet.
A special IEF ampholyte mixture - SinuLyte™ carrier ampholytes and MDH staining tablets complete the kit. IEF of MDH shows clear and easy-to-interpret expression of all five maize MDH genes. The variability of MDH is governed by several alleles per MDH gene which gives rise to more than 1000 possible combinations of MDH bands.
The genetic discriminative power of the MDH system allows development of a MDH hybrid purity test for the majority of maize hybrids. Moreover, genetic identity testing can also be done with a very high chance to detect genetic impurities other than inbreds, such as those arising from undesired pollination or undesired mixing of seed batches. This new method makes it possible to carry out a maize genetic purity test in 2 hours.
The SINUS MDH Gel Kit
• Highly reproducible gels with in-gel sample wells
• No toxic chemicals needed, such as the highly toxic acrylamide
• Easy handling of gels
• Easy staining tablets; No hustle with different staining recipes
• Much quicker and easier than starch gel electrophoresis
• No waste chemicals such as with Coomassie staining
• Much cheaper and faster than DNA purity testing