Abstract: A histological specimen infiltrating and embedding composition including paraffin and a copolymer of ethylene and vinyl acetate. The copolymer may be between 0.5 and 5% by weight of the paraffin. A surface active compatibilizer soluble in molten paraffin and which reduces the turbidity of the molten paraffin may be added to the composition in an amount between about 0.4% and 2% by weight of the paraffin.

Abstract: A colorimetric urea determination method, reagent, and reagent kit useful in end point and kinetic urea determination is disclosed. Urea in a liquid sample reacts with o-phthalaldehyde and a chromogenic compound in the presence of a linear long hydrocarbon chain amidobetaine to produce an intensely colored reaction product, the concentration of which is linearly related to the urea concentration in the sample.

Abstract: A complex of a long chain cationic surfactant and an organic anionic dye is useful in demonstrating the presence of and determining the concentration of fatty acids, compounds which hydrolyze to liberate fatty acids, or the activity of hydrolaze enzymes which produce fatty acids from a substrate.

Abstract: A colorimetric urea determination method, reagent, and reagent kit useful in end point and kinetic urea determination. Urea in a liquid sample reacts with o-phthalaldehyde and chromotropic acid or one of its salts in the presence of a linear long hydrocarbon chain amidobetaine to produce an intensely colored reaction product, the concentration of which is linearly related to the urea concentration in the sample.

Abstract: A quantitative colorimetric or spectrophotometric method of determining analyte albumin using a specie specific dye-based color reagent is disclosed. The method utilizes a standard solution comprising an aqueous solution of albumin of different specie than that of the analyte and a water soluble surfactant containing at least one hydrophobic group of contiguous carbon atoms. The surfactant is of a type and present in an amount such that the standard solution mimics, with respect to spectrophotometric response, an aqueous solution of the analyte when the standard solution and the analyte solution contain the same concentrations of albumin and color reagent.

Abstract: Colorimetric urea determination method and reagent in which urea in a liquid sample reacts with o-phthalaldehyde and chromotropic acid or one of its salts to produce an intensely colored reaction product whose concentration is linearly related to the concentration of urea in the sample and which follows Beer's law over a wide range of urea concentrations.

Abstract: Nitrilotris (methylene) triphosphonic acid and 1,3,6-napthalenetrisulfonic acid are used to stabilize solutions containing diazotized sulfanilic acid.

Abstract: A cholesterol standard solution containing a predetermined amount of cholesterol, alcohol, and a long chain alkyl substituted betaine.

Abstract: An aqueous reagent system for the quantitative determination of protein is disclosed. The system contains Coomassie Brilliant Blue G-250 dye, a monobasic strong acid having a pK.sub.a of less than 3 (e.g. HCl), a polybasic phosphonic acid (e.g. NTP), a water soluble, non-ionic surfactant characterized as being a block copolymer containing terminal polyethylene oxide segments separated by a polypropylene oxide segment. Preferably the system also contains a small amount of an alcohol such as methanol or ethanol.

Abstract: Stable aqueous solutions useful as standards in the determination of uric acid are disclosed. The solutions have a pH of about 6-7 and contain a buffer and a known concentration of uric acid present in solution as a salt of the pH-controlling buffer component. They do not contain any strong base such as lithium carbonate. The standards can be used in connection with either enzymatic or non-enzymatic procedures.

Abstract: Disclosed is a technique for accelerating the Hantzsch reaction, for the clinical determination of triglyceride, so as to permit the reaction to be analytically complete within 15 minutes at 37.degree. C. As is known, in this Hantzsch reaction, one mole of aldehyde is reacted in a solution predominantly containing alcohol and water with two moles of a betadicarbonyl compound in the presence of ammonia to yield, as a colored derivative, a lutidine. In the disclosed technique, the solution also contains an organic accelerator compound. This compound is capable of forming a clear solution with the mixture of components of the reaction solution and is further characterized as having an aprotic internal dipole such that said compound has a distinct center which is electron rich and a center which is electron deficient.

Abstract: A combination of hydrazine and a hydrazide is used to destroy residual diazotized sulfanilic acid in the Jendrassik and Grof procedure for determining bilirubin glucuronide.

Abstract: An aqueous solution useful in connection with a redox type spectrophotometric or colorimetric determination of uric acid in a biologic fluid is disclosed. The solution contains either a multivalent metallic ion reducible to a lower valence state by uric acid, a water soluble chelating compound capable of complexing with a metallic ion after reduction by uric acid to yield, in complexed form, a colored complex, or a combination of said ion and said chelating compound. The solution also contains, as an added constituent, imidazole, an alpha-amino acid, or a combination thereof. This constituent is present in an amount such that, when said solution contains a biologic fluid containing protein and uric acid, a buffer system such that the pH of the solution is 6 to 12, and a multivalent metal ion, the protein in the fluid does not significantly reduce said multivalent ions present in the solution.

Abstract: A method for the determination of amylase activity and a useful highly stable color reagent aqueous solution therefore are disclosed. The solution comprises, as a color reagent, an aromatic nitro containing compound such as 3,5-dinitrosalicyic acid, a color stabilizing chelating compound such as ethylenediaminetetraacetic acid, and a hydroxide base. Eliminating the necessity for centrifuging prior to the determination of amylase activity can be achieved by including potassium hydroxide for at least a part of the base in the solution.

Abstract: A one step method for the spectrophotometric determination of phosphorus in the presence of protein using molybdic acid is disclosed. Protein precipitation is avoided by including a long chain amine ethylene oxide adduct in the sample reagent mixture being analyzed.