[Rapid technic for preparation of thyroid ribonucleic acids without phenol].

Thyroid tissue was homogenized in 2 M LiCl. The homogenate was alloued to stand 1 h 30 min at 2 degrees C and then centrifuged. The pellet was suspended in 5% triisopropylnaphthalene sulfonic acid (the sodium salt), 0.05 M Tris--HCl, and 0.1 M NaCl (pH 8). After stirring and centrifuging, the supernatant containing the crude RNA was purified by filtration on Ultrogel AcA 22 (LKB, Sweden). Before adding the sample of crude RNA to the column, pronase was placed on the column. When pronase had entered the gel, we added the sample. The first peak contained pure RNA plus some DNA. The former was precipitated with 2 M LiCl. The RNA species obtained by this technique were undegraded and the yield was 30% better than that of the phenol technique.