Handbook for the bio-chemical laboratory / By John A. Mandel.

  • Mandel, John Alfred, 1865-1929.
Date:
1896
Catalogue details

Licence: Public Domain Mark

Credit: Handbook for the bio-chemical laboratory / By John A. Mandel. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    treated with MgS04 in substance until 100 c.c. of the liquid contains about 50 grms. of the salt. The so-called paramyosin or musculin separates. The filtered liquid is now treated with magnesium sulphate until each 100 c.c. of the liquid holds 94 grms. MgS04 in solution. The myosin which now separates is filtered, dissolved in water by the aid of the re- tained salt, precipitated by diluting with water, and, when necessary, purified by redissolving in dilute salt solution and precipitating with water. (Halliburton.) 2. Myosin may also be prepared by treating finely chopped meat, which has first been soaked in cold water until the muscles are white, with a 10-20$ ammonium-chloride solu- tion, allowing to stand for a few hours, stirring now and then. Filter this solution off and dilute with about 20 vols, water. The myosin separates in flakes which gradually settle to the bottom. This is washed 3 to 4 times by decantation, but not oftener, as then the myosin becomes insoluble. Dissolve now in ammonium-chloride solution and the myosin obtained therefrom, either by reprecipitating by diluting with water, or by removing the salt by dialysis. (Danilewshy.) Properties.—Myosin has the general properties of the globulins. It is completely precipitated by saturating with NaCl, also by MgS04, in a solution containing 94$ of the salt with its water of crystallization. Like fibrinogen it coagulates at 56° O. in a solution containing common salt, though the coagulation temperature may vary for myosins of different origin, and also for the same myosin in different salt solutions. It is soluble in dilute alkalies. Myosin decomposes hydrogen peroxide. Ovo-Yitellin. Preparation.—Shake the yolks of two eggs with 200 c.c. acid- free ether in a stoppered cylinder, then add 5 c.c. alcohol. A sticky, stringy precipitate will be formed. Remove the ether as well as possible and add 100 c.c. of a 10$ common salt