Abstract: A total cholesterol method includes the steps of (1) precipitation of serum proteins with a reagent containing ferric chloride in propionic acid, (2) color formation by heating aliquots of supernatant with propionic-sulfuric acid reagent, and (3) measurement of color intensities of test and standard reaction mixtures at 563 nm.

Abstract: An improved azobilirubin determination procedure utilizes a stable, dry lyophilized reagent. Dissolving the dry reagent in dilute hydrochloric acid produces a diazo reagent solution which is stable for several days. Cysteine hydrochloride may be added to the assay mixture to destroy excess diazo reagent, stabilize the final color, and remove interfering metal ions.

Abstract: A stable reagent for use in a rapid and sensitive globulin estimation procedure consists of 60-70 volumes of glacial acetic acid, 1-20 volumes of monomethyl ether of ethylene glycol, 5-15 volumes of phosphoric acid, 5-15 volumes of sulfuric acid, 0.2-0.6 volumes of twenty percent glyoxylic acid in aqueous solution, and 0.4-1.2 volumes of ten pecent ferric chloride hexahydrate in aqueous solution. The reagent is far more stable, sensitive, and tolerant of water in the reaction mixture than previously known reagents used in the glyoxylic reaction.

Abstract: A preweighed vial of lyophilized methemoglobin (ferrihemoglobin) provides a simple, stable, reproducible standard for colorimetric determination of total hemoglobin concentration in whole blood by the cyanmethemoglobin method. Conversion of the standard and of hemoglobin in blood samples to cyanmethemoglobin is accomplished with Drabkin's solution reconstituted from a dry powder and having an added non-ionic surface active agent (Brij-35). Color intensity is measured at 540 m.mu..