Removal of Excess Linker
- Excess linker may be removed by LMT agarose gel electrophoresis, a G-25 spin column, ultrafiltration or by PEG precipitation. (For example using a Centricon 30 or 50).
- Add 1 ml of deionized water to the Centricon 30 or 50 sample reservoir.
- Pipette reaction mixture containing DNA fragment- linker and non-ligated linkers into concentrator.
- Dilute up to 2 ml with deionized water.
- Dilute concentrate to 2 ml and centrifuge. Repeat.
- Recover concentrate by inverting concentrator and centrifuging at 300-1000 x g for 2 minutes.