I'm trying to understand the method which Ray Wu, developed to sequence the DNA 5' cohesive ends of a lamda phage. I'm reading these two papers written by him, but i stuck at the point where he uses the 32P nucleotides.
Structure and base sequence in the cohesive ends of bacteriophage lambda DNA
It's not clear to me, by reading the papers, the step in which he runs the polymerization of the DNA. Did he use all the 32P nucleotides at once or each one at a time. As i understood he made the DNA pol to use the tritiated nucleotides to fill in the gaps of the 5' cohesive ends and then he cleaves with a DNAase in many oligonucleotides which later fractionize with electrophoresis. If he added all tritiated nucleotides at once how did he recognize which one is at a specific place ?
Can someone describe the process in more detail using step by step aproach?
Thank you,