双脱氧法测定DNA序列,NTP, dNTPs and ddNTPs,ddNTPs,2,5,13,16,9,10,15,19,1,4,7,8,12,14,20,3,6,11,17,18,ddA,ddC,ddG,ddT,Separate and display these DNA fragments.,2,5,13,16,9,10,15,19,1,4,7,8,12,14,20,3,6,11,17,18,ddA,ddC,ddG,ddT,Labelled,Radioactive isotope labelled,PRIMER/TEMPLATE MIX DISTRIBUTED TO FOUR TUBES 4 dNTPs PLUS DNA POLYMERASE A RADIOACTIVE dNTPONE OF FOUR TUBES ADD ddAA SECOND ADD ddCTHIRD ddG FOURTH ddT,To Perform Sequencing,THUS:TUBE 1. PRIMER+TEMPLATE+4dNTPs + ddATPTUBE 2. PRIMER+TEMPLATE+4dNTPs + ddCTPTUBE 3. PRIMER+TEMPLATE+4dNTPs + ddGTPTUBE 4. PRIMER+TEMPLATE+4dNTPs + ddTTPALL TUBES CONTAIN DNA POLYMERASE,SCHEMATIC OF A TRADITIONAL SEQUENCING GEL AUTORADIOGRAM,SEQUENCE IS READ FROM BOTTOM TO GIVE 5 ACGCTAGGGCTCAA 3,The radioactive isotope-labelled di-deoxy nucleotides are replaced with 4 fluorescent derivatives, each base specificity being labelled a different colour; Therefore all four reactions combined; The DNA fragments are visualised by an automated spectroscope as they pass an observation The DNA fragments are identified by their fluorescent signals; The information is stored directly on a computer,Automated DNA sequencing,COMBINED REACTIONS,COMBINED REACTIONS,ACTIVATION LASER,Thermal cycle sequencing,