Nucleic Acids

adenine (purine), guanine(purine), cytosine(pyrimidine), thymine(pyrimidine) ,uracil(pyrimidine)

• diameter 20 angstroms
• Base pairs/ helical turn 10.5
• helix rise/base pair 3.4 angstroms
• right hand helix

• Z: rare, left handed
• A: crystallized form, right handed

• need DNA polymerase, primer and template
• Polymerase can either add ddntp or dntp
• The vary locations of the ddnTps can determine fragment size
• fragments run on gel

• Add DMT and attach 3' hydroxyl to Si resin
• remove DMT
• Add Nuc. with activating group and DMT
• Oxidate to form triester
• repeat until desired length formed
• remove DMT 
• remove cyanoethyl groups from phosphates
• cleave chain from silica support

• Deamination
• Depurination
• Pyrimidine dimers
• damaging agents
• DNA mismatch
• oxidative damage