WORKSTATION FOR AUTOMATED RECOVERY OF UNSTAINED DNA FRAGMENTS FROM GELS

MANY APPLICATIONS OF ELECTROPHORESIS INVOLVE SEPARATION OF DNA FRAGMENTS NOT ONLY FOR ANALYSIS BUT ALSO FOR SAMPLE ISOLATION AND PURIFICATION. RECOVERING DNA FROM ELECTROPHORETIC GELS AND PURIFYING IT IS AN INITIAL STEP IN PROCEDURES SUCH AS; THE POLYMERASE CHAIN REACTION (PCR), DEVELOPING CLONING LIBRARIES FOR PHYSICAL MAPPING AND DNA SEQUENCING. PRESENT PROCEDURES FOR EXTRACTING DNA FROM A GEL MEDIUM ARE TEDIOUS, PRODUCE INCONSISTENT RESULTS, AND CONSUME MANY HOURS OF A SKILLED TECHNICAL STAFF. SUCH MANUALLY INTENSIVE PROCEDURES ARE CLEARLY NOT SUITABLE FOR PROJECTS REQUIRING HIGH THROUGHPUT, IE., ISOLATION OF HUNDREDS OF DNA FRAGMENTS PER DAY. IN ADDITION, PRESENT TECHNIQUES FOR VIEWING DNA BANDS REQUIRE STAINING WITH ETHIDIUM BROMIDE DYE. ETHIDIUM BROMIDE IS A POTENT INHIBITOR OF MANY OF THE ENZYMES COMMONLY USED IN SUBSEQUENT CLONING STEPS OR PCR. BIOPHOTONICS PROPOSES TO ADDRESS THESE INADEQUACIES BY DEVELOPING A SEMI-AUTOMATED WORKSTATION TO PROVIDE; 1) DIRECT VISUALIZATION OF ELECTROPHORETIC PATTERNS OF UNSTAINED DNA USING ELECTRIC BIREFRINGENCE AS A DETECTION SCHEME; 2) MACHINE VISION TECHNIQUES TO LOCATE AND EXCISE DNA BANDS; AND 3) AUTOMATED EXTRACTION OF DNA FROM THE GEL MATRIX USING SPECIALLY DESIGNED ELECTROELUTION CELLS.