Properties of the Causative Agent of a Chicken Tumor: XII. Ultraviolet Light Absorption Spectrum of Purified Chicken Tumor Extracts Containing the Active Principle

Publisher Website
Google Scholar
Abstract
Although the principle inducing chicken tumor 1 can be obtained in a state of relative purity, little is known of its intimate constitution, and the mechanism of its action is still a matter of conjecture. In a series of studies from this laboratory (1, 2, 3), the principle was tentatively considered as a chemical constituent of the active tumor extracts and its separation was attempted by means of chemical methods. Recent fractionation provided solutions having a low solids content and chemical analysis pointed to a protein and phospholipoids as chief constituents of the active residue (4). The character of the purified extracts, which were clear and colorless, made the ultraviolet absorption method available for further analysis. Certain extracts were found to absorb ultraviolet light selectively, a broad absorption band being detected with a maximum at about λ 2550. Attempts were made to secure evidence indicating a correlation between the light-absorbing power of such extracts and the tumor-producing activity. Materials and Methods Preparation of Tumor Extracts: The mashed tumor tissue was extracted with a quantity of distilled water totalling in volume 20 times the weight of the original pulp. Usually 25 gm. of tumor pulp was used for a single experiment. No alkali was added. The extract was centrifuged for fifteen minutes at 2000 r.p.m., the supernatant fluid poured through sterile gauze and filtered through a Berkefeld V candle, the suction flask being kept on ice. The Berkefeld filtrate was concentrated by ultrafiltration in thimbles lined with collodion membrane.

This publication has 0 references indexed in Scilit: