Intact DNA purified from flow-sorted nuclei unlocks the potential of next-generation genome mapping

Scientists from Wageningen University & Research and other institutions presented technical challenges of obtaining sufficient high molecular weight (HMW) nuclear DNA due to cell walls which are difficult to disrupt. The obtained nuclei are embedded into agarose plugs for processing and isolating uncontaminated HMW DNA, which is a prerequisite for nanochannel-based next-generation optical mapping strategies.
They described important improvements for obtaining HMW DNA that they tested on Solanum crops and wild relatives. Flow sorted nuclei were embedded in agarose plugs and HMW DNA was purified with proteinase K and RNAse A and then isolated. Pulsed-field gel electrophoresis (PFGE) was used for DNA quality control. HMW DNA was subsequently labeled and analyzed on the Irys platform. Optical mapping (OM) data were then processed for de novo OM and hybrid assemblies.