One of the most important criteria of next-generation sequencing library preparation is to start with high-quality, high-molecular-weight genomic DNA. This is especially true for long read sequencing on the PacBio Sequel.
Determining the quality of high molecular weight DNA can be done using pulsed-field gel electrophoresis. Pulsed-field gels are more effective than regular gels at achieving differential separation of the small and large DNA molecules due to the constant change in the direction of the electric field in the gel. Pulsed-field gel electrophoresis can resolve DNA out to 100 kb and beyond.