2016-1-7 · storage of homogenized sample for future extraction. B. Phase Separation 1. Incubate the homogenized sample for 5 minutes at room temperature. (If tubes are frozen, thaw in a bucket of wet ice before proceeding to room temperature incubation.) 2. In a chemical fume hood, add 0.2 mL of chloroform per 1 mL of TRIzol reagent. 3.