Generally, sonication and glass bead have been used for extracting the spore proteins of Bacillus sp. I used Hielscher UP400S sonicator to extract spore coat proteins for the species I stated above. I tried 30% amplitude with 0.5% cycles for 10 min. After that, I spinned down the sonicated samples at 9,000 g for 5 min and the supernatant was treated with LDS buffer (4X) and reducing agent (10X) as stated by the protocol from the company. Then, heated at 70 degress for 10 min and loaded in NuPAGE 4-12% Bis-Tris gel. HOWEVER, no band! It would be awesome if anyone can help. Thanks.