Directions for laboratory work in physiological chemistry : for the use of students in the University and Bellevue Hospital Medical College / Holmes C. Jackson.

  • Jackson, Holmes C. (Holmes Condict), 1875-
Date:
1902
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Licence: In copyright

Credit: Directions for laboratory work in physiological chemistry : for the use of students in the University and Bellevue Hospital Medical College / Holmes C. Jackson. Source: Wellcome Collection.

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    5. To 5 c.c. of this solution add (NH4)2 S04 (salt) to satu- ration. Note results and see if the precipitation is complete in each case. (d) Acidify 10 c.c. of the albumin solution with HC1. 1. To 5 c.c. of this solution add 2 drops of phosphotung- stic acid. 2. To 5 c.c. of this solution add 2 drops of potassium- mercuric-iodide. (e) To successive portions of 5 c.c. of the albumin solution add a few drops of CuS04; neutral and basic lead acetate; HgCl2; trichloracetic acid. Make careful notes of the results of the above reactions, and where possible write equations. SIMPLE PROTEIDS. Albumins. (a) Coagulation. Heat 5 c.c. of the albumin solution and then add one or two drops of acetic acid. The albumin separates out in an insoluble, flocky (coagulated) form. Why is the addition of the acetic acid necessary? Try to dissolve the coagulum in some of the ordinary proteid solvents. Make 5 c.c. of the albumin solution faintly alkaline, and heat. Note differences. (b) To 10 c.c. of the albumin solution add (NH4)2S04 to saturation. Note result and compare with experiment (c) 5, p. 11. Filter off the precipitate and test the filtrate with the Biuret test. (c) To 10 c.c. of the albumin solution add MgS04 to sat- uration. Compare this result with that of experiment (c) 4,