The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 26, 1992
Filed:
Apr. 26, 1990
Mark F Adams, Tacoma, WA (US);
Melvin R Knudson, Tacoma, WA (US);
Larex International, Inc., Tacoma, WA (US);
Abstract
The invention is a very highly refined arabinogalactan gum falling within the molecular weight range of 6,000-2,500,000 and having a tannic acid equivalent of less than about 0.5 mg/g. The preferred product will have a molecular weight within the range of 6,000-1,300,000 and tannic acid equivalent no higher than about 0.25. The product is nearly colorless and is tasteless and odorless. it is prepared by first making a crude water extract of a natural source such as larch wood. This extract is next refined by the addition of an active MgO to precipitate the bulk of the lignans and iron containing compounds. Following that it is processed through a membrane no larger than about 0.45 .mu.m to remove any species having molecular weights in excess of about 2,500,000. The permeate may then be treated on successively smaller membranes down to about 6,000 daltons. The permeate through the 6,000 dalton membrane contains virtually all of the monomers, homopolymers, and other materials that would contribute to the osmolality of a resulting solution of the ultrarefined arabinogalactan. The product is especially useful for medical research involving cell separation by density gradient since its contribution to the osmolality of a solution is essentially zero.