Triglycerides are determined by enzymatic saponification with lipase and measurement of the liberated glycerol by carrying out the saponification in the presence of carboxylesterase and an alkali metal or alkaline earth metal alkyl sulfate; reagents are provided for carrying out the process and comprise a buffer and, as a saponification agent, lipase, carboxylesterase and the alkali metal or alkaline earth metal alkyl sulfate, and a glycerol detection system.

In a mixture of ethylene and acetylene, the ethylene is selectively oxidized to formaldehyde. This oxidation is used in the determination of nitrogenase (nitrogen fixation) activity where ethylene produced by the enzyme from added acetylene, has to be measured. The formaldehyde produced from the ethylene is proportional to the enzyme activity, and can be assayed colorimetrically or otherwise.

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.

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 le...

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 le...

Salicylate content in blood serum or the like can be spectrophotometrically determined using a new reagent solution. The reagent solution contains ferric ions, tungstic acid, phosphoric acid and a polyoxyethylene/polyoxypropylene block copolymer which is an effectively non-ionic surfactant. Preferably, when human blood sera is used, the standard employed for calibration contains a base so that both the standard and the reagent solution containing unknown are at the same pH. The described techniq...

An improved reagent system for determining calcium by the orthocresolphthalein complexone color reaction. The reagent utilizes an alkaline buffer containing an aminoloweralkanol providing a pH of about 10.2 - 10.5. A method for using the reagent is also described. The composition is stable for extended periods.

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.

A method of measuring glycosylated hemoglobin featuring, in one aspect, providing a sample containing hemoglobin, including an unknown amount of glycosylated hemoglobin, contacting the sample with an oxidizing agent to generate formaldehyde, and measuring the formaldehyde as a measure of glycosylated hemoglobin, the measuring being carried out by reacting the formaldehyde with a water-soluble amine or an ammonium salt and a .beta.-diketone to generate a fluorescent compound whose fluorescence is...

Method and apparatus for the determination of biomass in a suspension, such as a culture, in `real` time and a fermentation process using the method. In the method the electrical capacitance of the suspension is measured and from the measurement the volume fraction of the suspension enclosed by the cytoplasmic membranes of the cells (biovolume) is determined.