Author Question: When DNA is replicated, the new chain is synthesized in what ... (Read 34 times)

FButt · **on:** Aug 23, 2018

When DNA is replicated, the new chain is synthesized in what direction?

Question 2

Describe, in general terms, the steps involved in the automated synthesis of the DNA sequence GCT.

choc0chan · **Reply #1 on:** Aug 23, 2018

Answer to Question 1

As DNA is replicated, the new chain is synthesized in the 5' to 3' direction.

Answer to Question 2

Step 1 Attachment of 5'-DMT-N-benzoyl-2'-deoxyaguanosine to the polymer support by a 3' ester linkage.
Step 2 Deprotection of the 5'-hydroxyl by cleavage of the DMT ether with dichloroacetic acid in CH2Cl2.
Step 3 Phosphite formation between the free 5'-hydroxyl of the polymer-bound N-protected 2'-deoxyguanosine and the phosphoramidite protected 5'-DMT-2'-deoxycytidine in the presence of tetrazole followed by oxidation to the phosphate triester with I2.
Step 4 Repeat step 2 to deprotect the 5'-hydroxyl of the polymerGC.
Step 5 Repeat step 3 to form the phosphate triester between 5'-hydroxyl of 2'-deoxycytidine residue and phosphoramidite protected 5'-DMT-N-benzoyl-2'-deoxythymidine.
Step 6 Cleave all protecting groups from the heterocyclic bases from the phosphates, as well as cleave the ester bond holding the DNA to the silica by treatment with aqueous ammonia.