A Manual of selected biochemical methods as applied to urine, blood and gastric analysis

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1921 Excerpt: ...It is filled five or six times with cold water, or it is allowed to soak five minutes in cold water. A knife blade is run around the upper rim, so as to loosen the sac from the rim of the test-tube, and a few cubic centimeters of water are run down between the sac and the glass tube. By gentle pulling the tube is extracted, after which it is preserved by complete immersion in water. The Salt Solution.--The blood or serum is dialyzed against an 0.8 per cent sodium chloride solution. Before applying the test, it is necessary to ascertain that the solution is free from acids other than carbonic. To determine this, a few cubic centimeters of the salt solution are placed in a Jena test-tube and 1 or 2 drops of the indicator added, whereupon a yellow color appears. On boiling carbon dioxide is expelled, and the solution loses its lemon color and takes on a slightly brownish tint. In the absence of this change other acids are present, and the salt solution is therefore not suitable. If, on the other hand, on adding the indicator pink at once appears, the solution is alkaline and hence cannot be used. Preparation of Standard Colors.--Standard phosphate mixtures are prepared according to Sorensen's directions as follows: 1/15 mol. acid or primary potassium phosphate. 9.078 gms. of the pure recrystallized salt (KH2PO4) is dissolved in freshly distilled water and made up to 1 liter. 1/15 mol. alkaline or secondary sodium phosphate. The pure recrystallized salt (Na2HPO4-12H2O) is exposed to the air for from ten days to two weeks, protected from dust. Ten molecules of water of crystallization are given off and a salt of the formula Na2HPO4-2H2O is obtained. 11.876 gms. of this is dissolved in freshly distilled water and made up to 1 liter. The solution should give a dee...