The lecture includes DNA sequencing procedure by Sanger. The process involves the termination of DNA replication by the use of dideoxy nucleotides made of four different bases of DNA. It involves the DNA polymerisation by the PCR but the reaction mixture consist of primer, dNTPs, DNA template, buffer, DNA polymerase and ddNTPs consisting of pentose sugar lacking –OH group at 3′ position. The chain extension takes place till the DNA polymerase do not encounter ddNTPs. After PCR the products are analysed on AGE and finally sequenced from bottom to up.