- Tris: buffers the soluton at pH8
- EDTA (TE): binds divalent cations; weakens the bacterial cell wall and removes needed cofactors for nuclease enzymes that degrade DNA
- GTE: osmotic stabilizer
- SDS: lyses cells; dissolves the lipids in the PM and denatures proteins in the cell wall and cytoplasm
- NaOH: denatures proteins and DNA
- Neurtalizes the preparation so that the plasmid molecules can renature
- Precipitates proteins and lipids.
- K+ ions: neutralize the negative charges on the phosphates in DNA, clumping them.