Animal tissues, such as blood, liver, brain and thymus, are easily homogenized by bead beating. The small amount of connective tissue allows for these soft tissues to be processed very efficiently. Soft animal tissues can be homogenized with a buffer or cryogenically, the latter method being more useful for isolating high molecular weight DNA. Samples less than 100 mg can be processed in disruption tubes with 1.4-3.0 mm zirconium beads. Smaller samples can also be homogenized in polypropylene deep well plates with one 5/32” grinding ball or 6 mm satellite per well.
Larger samples are best homogenized in grinding vials. Processing up to 200 mg of animal tissue is best done in a 4 ml polycarbonate vial with one 5/16” or 3/8” stainless steel grinding ball. Up to two grams of animal tissue can be homogenized in a 15 ml polycarbonate vial and two 7/16” stainless steel grinding balls. In both instances, grinding can be done with buffer, or cryogenically without buffer. Cryogenic grinding is best done using Cryoblocks to prevent excessive melt back of the sample. Polyethylene vials should be used instead of polycarbonate when using extraction buffers containing phenol and/or chloroform. Zirconium oxide grinding satellites are chemically resistant and can be used with corrosive extraction buffers.
|Disruption Tubes (2 ml)||Deep Well Plates (Round wells)||4 ml Vials||15 ml Vials|
|Sample Mass||20 mg||20 mg||100-200 mg||Up to 2 gm|
|Buffer Volume||600 µl||200 µl||1 ml||6 ml|
|Grinding Balls||8 x 2.8 mm||1 x 5/32”||1 x 3/8”||2 x 7/16”|
|Processing Time||2 minutes||2 minutes||2-3 minutes||3-5 minutes|
|Bead Beater Speed||High||High||High||High|
|Balls:||2.8 mm Stainless Steel (GBSS 089-100-07), 5/32’’ Stainless Steel (GBSS 156-5000-01), 3/8’’ Stainless Steel (GBSS 375-1000-02), 7/16’’ Stainless Steel (GBSS 437-1000-03)|
|Pre-filled Tubes:||2.8 mm Stainless Steel (PFSS 2800-50-20)|
|Disruption Tube:||2 ml Skirted Disruption Tubes (PPDT 02-500-13)|
|Vial Sets:||24 Well PC Vial Set (PCVS 04-240-03), 15 ml Polycarbonate Vial Sets (PCVS 15-050-22)|
|Homogenization Vessel:||See Appendix A|
|Homogenizers:||Cryogenic grinding requires a GenoGrinder® or Mini G™ (Appendix A)|
|Cryogenic Option:||Cryoblocks (4 ml and 15 ml)|