DNA extraction

What step in inspin column DNA extraction do you put proteinase K to?

• Lysis

• Binding

• Washing

• Elution

Main function of proteinase K?

• contain chaotropic salt to promote DNA binding to silica membrane

• Break down proteins in cell membrane, nucleases

• Disolve and remove impurities

• Neutralize DNA backbone

What is the primary purpose of an elution buffer?

• Bind DNA to silica membrane

• Wash away impurities from DNA

• To release purified DNA from silica membrane

• Break down cell walls to access DNA

Why there are two different washing buffers with two different ethanol concentration?

• Higher concentration to wash out the impurities from DNA - bound silica while lower concentration is a stock solution

• Higher concentration as a stock solution while lower concentration to wash out the impurities from DNA - bound silica

• Higher concentration to wash out the impurities from DNA-bound silica while lower concentraotion to remove the remaining impurities

• Both will be mix together as one solution to remove / wash out impurities from DNA - bound silica

How the DNA can bound to the silica column ?

• Small filter of the silica

• Due to the electrostatic interaction of Na+ from salt and O- from the silica

• negatively charged of DNA

• DNA precipitate to the silica column