# US 2018/0127799 A1 · Reagents and Methods of Use With Automated Analyzers For Obtaining A Specific Gravity Index For Urine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0127799 A1 - Document ID: US20180127799A1 - Status: Published application - Kind: A1 - Application number: 15/651,334 - Filed: 2017-07-17 - Published: 2018-05-10 - Earliest claimed: 2016-07-18 - Assignees: Vision Diagnostics, Inc. - Applicants: Vision Diagnostics, Inc. - Inventors: Jerry W. Denney - Web page: https://patentgrep.com/patent/US20180127799A1 ## CPC - C12Q 1/34: involving hydrolase - G01N 33/94: involving narcotics {or drugs or pharmaceuticals, neurotransmitters or associated receptors} - G01N 2333/938: acting on beta-galactose-glycoside bonds, e.g. beta-galactosidase - C12Q: MEASURING OR TESTING PROCESSES INVOLVING ENZYMES, NUCLEIC ACIDS OR MICROORGANISMS (immunoassay G01N33/53); COMPOSITIONS OR TEST PAPERS THEREFOR; PROCESSES OF PREPARING SUCH COMPOSITIONS; CONDITION-RESPONSIVE CONTROL IN MICROBIOLOGICAL OR ENZYMOLOGICAL PROCESSES - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) ## Abstract Reagents and methods for using automated laboratory equipment to determine whether the specific gravity of a urine sample is out of normal range as an indication of adulteration. The sodium (Na+) and potassium (K+) normally found in a urine sample can be used as markers. A sodium-potassium dependent β-galactosidase can be utilized with o-nitrophenylgalactoside (o-NPG) which is cleaved into o-nitrophenol, which turns the sample yellow. The sample can be analyzed by spectrophotometry methods utilized in most clinical analyzers at a pre-determined primary wavelength to obtain a Specific gravity Index (SGI). Measurements of the SGI that are outside a known normal range can indicate that the sample integrity has been compromised. ## Claims ### Claim 1 An assay method for calculating a specific gravity index of a biological sample, the assay method comprising: reacting the biological sample with a reagent that forms o-nitrophenol in direct relation to the amount of sodium and potassium in the biological sample, so as to change the color of the biological sample; analyzing the color of the reacted biological sample with a spectrophotometer; obtaining a measure of light absorbance for the reacted biological sample; and calculating a Specific Gravity Index based on the light absorbance measurement. ### Claim 2 (depends on 1) The assay method according to claim 1, wherein the light absorbance is measured between 405 nm and 410 nm. ### Claim 3 (depends on 2) The assay method according to claim 2, wherein the Specific Gravity Index is used to determine whether the total amount of sodium and potassium in the biological sample is within a normal range, where a total amount of sodium and potassium that is outside a normal range is indicative of adulteration. ### Claim 4 (depends on 3) The assay method according to claim 3, wherein the reagent comprises a β-galactosidase that reacts with the sodium and potassium in the biological sample. ### Claim 5 (depends on 4) The assay method according to claim 4, wherein the method is conducted in an automated system for analyzing biological samples. ### Claim 6 (depends on 1) The assay method according to claim 1, wherein the biological sample is urine. ### Claim 7 An assay method for obtaining a Specific Gravity Index for a biological sample, the method comprising: reacting the biological sample with a first reagent comprising o-nitrophenylgalactoside; then reacting the biological sample with a second reagent comprising β-galactosidase, such that the β-galactosidase is converted to yellow o-nitrophenol in an amount that is in direct relation to the amount of sodium and potassium present in the biological sample; analyzing the yellow color of the reacted biological sample with a spectrophotometer; obtaining a measure of light absorbance for the reacted biological sample; and calculating a specific gravity index based on the light absorbance measurement. ### Claim 8 (depends on 7) The assay method according to claim 7, wherein the light absorbance is measured between 405 nm and 410 nm. ### Claim 9 (depends on 8) The assay method according to claim 8, wherein the Specific gravity Index is used to determine the total amount of sodium and potassium in the biological sample, where a total amount of sodium and potassium that is outside a normal range is indicative of adulteration of the sample. ### Claim 10 (depends on 9) The assay method according to claim 9, wherein the assay is conducted in an automated system for analyzing biological samples. ### Claim 11 (depends on 7) The assay method according to claim 7, wherein the biological sample is urine. ### Claim 12 A kit for measuring the amount of total sodium and potassium in a biological sample, the kit comprising: a first reagent comprising o-nitrophenylgalactoside; and a second reagent comprising β-galactosidase that, in the presence of the sodium and potassium in the biological sample, will cleave the o-nitrophenylgalactoside into o-nitrophenol producing a yellow color in the biological sample; such that the sample, when analyzed spectrophotometrically, can provide a Specific gravity Index indicative of the amount of total sodium and potassium in the biological sample. ### Claim 13 (depends on 12) The kit according to claim 12, wherein the first reagent and the second reagent are used in an automatic system. ### Claim 14 (depends on 13) The kit according claim 13, further comprising a calibrator for calibration of the automatic system. ### Claim 15 (depends on 14) The kit according to claim 14, wherein the calibrator comprises magnesium.