not recommended for high-salt protein solutions

- add 4 vol. cold (fresh from the -20 C freezer) acetone or ethanol
- keep 30 min or longer at -20 C
- spin: 5'min at top speed (eppies) or 20 min at 4-6k rpm (50-ml tubes)
- remove sup
- dry pellet 2 min at rt
- put pellet in desired buffer

- add 4 vol. 50% TCA
- 30 to 60 min on ice, or o/n in the fridge
- spin 10 min at top speed (eppies) 30 min at 4-6 k rpm (50-ml tubes)
- remove sup
- optional: remove residual TCA by washing pellet in 20 mM Tris pH 8/70% ethanol
- put pellet in desired buffer

protein loading dyes such as Laemmli buffer (for SDS-PAGE) turn yellow due to leftover TCA in protein pellets. add concentrated NaOH in 0.5 ul-steps untill the blue color comes back again