Incomplete lysis — visible debris or turbid supernatant (Protein Extraction)

Question

Accepted Answer

After homogenization / lysis there are visible chunks or debris in the tube and the supernatant is turbid; SDS-PAGE shows missing or weak bands. Common causes: 1) Tissue/cells were not fully homogenized or ground 2) Lysis buffer choice or strength was wrong for the sample type 3) Lysis time too short 4) Sample was too sticky/viscous to lyse effectively 5) Sample-to-buffer ratio overloaded the lysis capacity Solutions: 1) Fully homogenize / grind on ice (pestle, bead beater, or sonication) 2) Choose a lysis buffer appropriate for the sample type (RIPA for general, NP-40 mild, urea/SDS for hard tissues) 3) Extend lysis time and mix periodically 4) Dilute the sample or increase lysis buffer volume 5) Lyse in smaller batches