Methods and Reagents Useful for Verification of the Integrity of a Urine Sample and the Detection of Counterfeit Urine

Abstract

The problem of detecting whether a urine sample is true human urine or a counterfeit urine product is solved by the use of reagent systems that detect two markers normally present in human urine. The markers acid phosphatase and alkaline phosphatase catalyze the substrates thymolphthalein monophosphate and p-nitrophenol phosphate, respectively. These substrates are formulated as spot tests on a dip stick or as reagents for use in automated chemical analyzers. The presence of the markers can be qualitatively detected by color-changes in the sample, formed by the pH-specific chromogens that result from catalysis of the substrates with the markers. The control reagent can further indicate whether a counterfeit urine product contains one or both of the chromogens.

I claim: 
     
         1 . A reagent, adapted to be utilized in an automated analyzer to detect a marker in a urine sample, the reagent comprising:
 a first component having an alkaline pH;   a second component having an acid pH that comprises p-nitrophenyl phosphate, which is catalyzed by the marker in the urine sample to produce a chromogen.   
     
     
         2 . The reagent according to  claim 1 , wherein the marker in the urine that catalyzes the p-nitrophenyl phosphate is alkaline phosphatase. 
     
     
         3 . The reagent according to  claim 2 , wherein the color is spectrophotometrically measurable at approximately 405 nm. 
     
     
         4 . The reagent according to  claim 1 , wherein the first component has a pH of about 10.2+/−0.05. 
     
     
         5 . The reagent according to  claim 1 , wherein the second component has a pH of about 6.5+/−0.01. 
     
     
         6 . A method for utilizing an automated analyzer to detect a marker in a urine sample, the method comprising:
 a) obtaining a reagent, according to  claim 1 ;   b) combining an aliquot of the urine sample with the first component of the reagent to form a test sample;   c) further combining the test sample with the second component of the reagent to form a reacted sample; and   d) detecting formation of a chromogen in the reacted sample that is indicative of the presence of the marker in the urine sample.   
     
     
         7 . The method according to  claim 6 , wherein the marker is alkaline phosphatase and the chromogen is p-nitrophenol. 
     
     
         8 . The method according to  claim 6 , further comprising allowing the automated analyzer to warm the test sample. 
     
     
         9 . The method according to  claim 8 , wherein the formation of a yellow color detectable by the automated analyzer in the test sample is indicative of an indicator dye in the urine sample. 
     
     
         10 . The method according to  claim 6 , wherein the first component has a pH of about 10.2+/−0.05. 
     
     
         11 . The method according to  claim 6 , wherein the second component has a pH of about 6.5+/−0.01. 
     
     
         12 . A method for utilizing an automated analyzer to detect an adulterated urine sample, the method comprising:
 a) obtaining a reagent according to  claim 1 ;   b) combining an aliquot of a urine sample with the first component of the reagent to form a test sample; and   c) detecting the formation of a color in the test sample, which indicates an adulterated urine sample.   
     
     
         13 . The method according to  claim 12 , wherein the color is detected at about 405 nm. 
     
     
         14 . The method according to  claim 12 , wherein the adulterated urine sample comprises an indicator dye activated by the alkalinity of the first component to form the color. 
     
     
         15 . The method according to  claim 12 , further comprising allowing the automated analyzer to warm the test sample, wherein the color is detected during warming of the test sample. 
     
     
         16 . The method according to  claim 12 , wherein the first component has a pH of about 10.2+/−0.05.