Bayer Corporation

Bayer Corporaton

Robert J Schaeper

Michael J Pugia

Gary M Johnson

Sally E Cahill

The present invention involves a composition and method for the determination of enzymatic activity or enzyme substrate concentration in a fluid test sample in which the enzyme catalyzes a reaction in a reagent system to provide a detectable response indicative of the concentration of the enzyme or enzyme substrate in the test sample. A measured amount of a protease capable of eliminating the enzymatic activity is included in the reagent composition, so that when a measured amount of test sample is treated, the reaction producing the detectable response will have a definite end point. The invention is particularly useful in conjunction with the determination of leucocytes in urine wherein the leukocytes are lysed to release their human leucocyte elastase which hydrolyzes a chromogenic ester to provide a phenol which then reacts with a diazonium salt to form a colored azo dye.

Enzyme determination with protease inactivation

Disclosed is an improvement in the method of determining protein in an aqueous fluid such as urine by contacting the fluid with a reagent system of a buffer and a protein error indicator. The improvement involves carrying out the determination in the presence of a glass/cellulose combination.

Glass/cellulose as protein reagent

Disclosed is an test for the detection of protein in urine by the use of a reagent system containing a buffer and a protein error indicator. The method involves the use of tartaric acid as cation sensing buffer in combination with a non-cation sensing buffer as the buffer system in order to reduce the incidence of false positive results while using less total buffering material.

Method for the detection of protein in urine

A test device for determining the presence of leukocyte cells, esterase or protease in a test sample is disclosed. The test device comprises a carrier matrix having a reagent composition incorporated therein, wherein the reagent composition comprises a lactate ester having the structure ##STR1## wherein A is an alcohol blocking group, and wherein B--O-- is a residue of compound B--OH and provides a detectable response when the lactate ester is hydrolyzed; and a buffer. In a preferred embodiment, the lactate ester has the structure ##STR2## wherein X is O, S or NR.sup.2, R is aryl or lower alkyl, R.sup.1 is hydrogen or lower alkyl, and R.sup.2 is hydrogen, lower alkyl or aryl.

Test device for determining the presence of leukocyte cells, esterase or

A composition and method for determining the presence of leukocyte cells, esterase or protease in a test sample are disclosed. The composition contains a lactate ester having the structure ##STR1## wherein A is an alcohol blocking group, and wherein B-O- is a residue of compound B-OH and provides a detectable response when the lactate ester is hydrolyzed; and a buffer. One class of lactate ester has the structure ##STR2## wherein X is O, S or NR.sup.2, R is aryl or lower alkyl, R.sup.1 is hydrogen or lower alkyl, and R.sup.2 is hydrogen, lower alkyl or aryl.

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South Bend, IN, United States of America

Robert J Schaeper