Handbook for the bio-chemical laboratory : including methods of preparation and numerous tests arranged alpabetically / by John A. Mandel.

Date:
1896
Catalogue details

Licence: Public Domain Mark

Credit: Handbook for the bio-chemical laboratory : including methods of preparation and numerous tests arranged alpabetically / by John A. Mandel. Source: Wellcome Collection.

Provider: This material has been provided by the Royal College of Physicians of Edinburgh. The original may be consulted at the Royal College of Physicians of Edinburgh.

    34/120 (page 22)
    MetluBinoglobin. Preparation.—On treating a concentrated solution of oxy- liEemoglobin with a sufficient quantity of a concentrated solution of potassium ferricyanide to give the mixture a porter-brown color, metliEenioglobin will be formed. After cooling to 0° C. add vol. alcohol cooled to 0° 0., and allow the mixture to stand a few days in the cold. The crystals ob- tained maybe easily purified by recrystallization from water by the addition of alcohol. (Pig’s blood is better adapted for the preparation of metliEemoglobin than dog’s blood.) Properties.—Methaemoglobin crystallizes in brownish-red needles, prisms, or six-sided plates. It dissolves readily in water, and this solution becomes red on the addition of alkali. The spectrum of methaemoglobin shows three absorjition- bands, one in the red about half way between C and D, the other two between D and E, which resemble the position of the oxyhaemoglobin lines, but on careful measurement are found to be different. Fibrin Ferment. Blood-serum is mixed with 10 to 15 times its volume of absolute alcohol; by this means the proteids are precipitated, as also the ferment. The precipitate is allowed to stand a few months with the alcohol, which renders the proteids insoluble. Filter the precipitate off and dry in de- siccator over sulphuric acid. The ferment is separated from the other bodies by extracting with water, which dissolves the ferment. {A. Schmidt.) Properties.—A solution of the ferment will coagulate peri- cardial and similar fluids or solutions of fibrinogen. It is most active at about 40° 0. It is diminished in action at 0° 0., and entirely destroyed on heating its solutions to 73°-75° C.