MEMBRANE-MEDIATED SAMPLE LOADING FOR AUTOMATED DNA-SEQUENCING

A new and improved sample loading method for DNA sequencing gels using oligo/polynucleotide binding membranes is described. The labeled DNA sequencing fragments were spotted onto a membrane sample loader, which was then placed in contact with the precast polyacrylamide separation gel. In this way, the time-consuming sample well loading by the tedio us pipetting procedure was avoided. The spotted DNA fragments remain i mmobilized on the membrane until the separation process is initiated b y the application of the electric field (an active DNA release mechani sm). This novel technique enables sample loading outside of the separa tion platform, thereby allowing full utilization of various automated sample preparation and liquid handling (robotics) systems, resulting i n ''real'' automated DNA sequencing. The loaded membranes can be store d for more than 24 hours for later use.