This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Desjardins, R. Articles by Arendell, J. P. Search for Related Content PubMed PubMed Citation Articles by Desjardins, R. Articles by Arendell, J. P.

A Large-Scale Procedure for Isolation of Nucleoli from Walker Tumors¹

Department of Pharmacology and the Tumor By-products Laboratory, Baylor University College of Medicine, Houston, Texas

A method is presented for isolation of 2–10 gm of highly purified nucleoli from Walker tumors. Initially, 0.5–1 kg of tumor was minced in a specially devised stainless steel mincer. The minced tissue was then homogenized in a continuous tissue homogenizer in 0.25 M sucrose containing 3.3 mM CaCl₂. The nuclear preparation, obtained by continuous flow centrifugation, was subjected to sonic oscillation with a sonifier for periods of 1–2 min. The preparation was layered over 0.88 M sucrose and centrifuged for 20 min at 900 x g in a centrifuge with a large capacity to provide the nucleolar pellet. Electron microscopic and chemical analyses indicated that the preparation was highly purified and the nucleoli were morphologically similar to those in the tumor cells. The yield of nucleoli/kg of tissue was approximately 7 x 10¹⁰, i.e., 4.3 ml of packed nucleoli. Sucrose gradient sedimentation profiles revealed that the isolated tumor nucleoli contained relatively larger amounts of 35 and 45 S RNA than the whole nuclear preparation and very small amounts of 18 S RNA.

¹ These studies were supported in part by grants from the American Cancer Society, The Jane Coffin Childs Fund, the National Science Foundation, and USPHS Grant CA-08182.

Received 6/29/65.