A system for automated DNA electrophoresis, molecular hybridization and electronic detection: I Electrophoresis and hybridization

Abstract

Abstract We have designed and constructed a computer‐controlled, fully automated system for Southern‐type nucleic acid hybridization analysis. Restriction enzyme digests of DNA are placed into sample wells of the gel contained on a nine‐fingered plastic frame. The 32 ‐labeled probe is loaded into the hybridization chamber. Instructions for all the subsequent steps in the fully automated process are specified by the operator's answers to questions which appear on the computer screen at the start of the experiment. The system performs horizontal submarine electrophoresis. An adjustable endpoint detector concludes electrophoresis. Automatic voltage/temperature feedback control maintains maximum allowable voltage while keeping the temperature constant. Following electrophoresis a robot arm moves the gel frame from station to station. The system then affixes the separated fragments to a solid phase matrix, denatures, neutralizes, hybridizes, washes, dries and detects the 32 P according to the specifications preprogrammed by the operator. The results, printed out by the computer, give a plot of radioactivity versus distance from the origin for each of the nine simultaneous hybridizations.