Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
  • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
  • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
  • G01N33/70—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing involving creatine or creatinine
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T436/00—Chemistry: analytical and immunological testing
  • Y10T436/10—Composition for standardization, calibration, simulation, stabilization, preparation or preservation; processes of use in preparation for chemical testing
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T436/00—Chemistry: analytical and immunological testing
  • Y10T436/14—Heterocyclic carbon compound [i.e., O, S, N, Se, Te, as only ring hetero atom]
  • Y10T436/145555—Hetero-N
  • Y10T436/147777—Plural nitrogen in the same ring [e.g., barbituates, creatinine, etc.]

Definitions

• ABSTRACT A colorimetric process for the quantitative determination of creatinine in blood serum or urine wherein an alkaline pH in the approximate range of 11.0 to 13.5 is maintained during colorimetry evaluation and in which urea and a detergent are caused to react simultaneously and synergistically with the serum or urine protein to prevent extraneous chromogen formation in the conventional alkaline-picrate reaction for creatinine.
• creatinine is a waste product removed from the blood stream by the kidneys. Since creatinine is excreted only by way of the kidneys, for instance, kidney disease can be diagnosed from an increased creatinine content measured in the serum. Quantitative creatinine determination also is useful in the diagnosis of urinary obstruction, intestinal obstruction, and nephritis, an inflamation of the kidneys caused by infection, the degenerative process or vascular disease. In U.S. Pat. No. 3,705,013, there is discussed some features of critical creatinine determinations desired for accurate and effective diagnosis of diseases.
• the Jaffe reaction is not considered specific for creutinine in the presence of protein, glucose, and a number of unknown substances present in normal human sera. Methods designed to improve specificity have, for the most part, relied on use of protein-free filtrates. In addition to utilization of protein-free filtrates, so-called "specific methods" for creatinine have been introduced in which the filtrate is used in adsorption-elution techniques; see Brod, J. and Kotatko, J., J. Cas. Lek. Ces. 88,665 Excerpta Medica, Amst. 3,477 (1950); Hare. R. 5., Proc. Soc. Exp. Biol. N.Y., 74,148 I950); Haugen. H. N.
• the second avenue of approach consists of introduction of suppression of non-creatinine, Jaffe-positive chromogens by varying reaction pH or incorporating reagents shown to suppress the effect of color interference by non-creatinine substances.
• Reagent blanks or running serums at two different pHs are an integral part of all of these approaches as seen from Raabo, E. and Walloe-Hansen, P. Scand. J. Clin. Lab. Invest. 29,297 (1972); Heinegard, D. and Tiderstrom, 6., Clin. Chim. Acta 43,305 (1973).
• the invention provides a procedure for the detection of creatinine which employs an alkaline-picrate reagent which substitutes sodium phosphate for the more commonly used sodium hydroxide or lithium hydroxide.
• Urea is incorporated into the alkaline-picrate reagent.
• An aralkane sulfate detergent of sodium, potassium or lithium, such as sodium dodecyl sulfate (sodium lauryl sulfate) and sodium borate are added to the reagent. In this procedure, suppression of interfering chromogens is maximized and the serum blank is eliminated.
• the reagent formulations are as follows:
• Sodium dodecyl sulfate solution 4 grams/100 ii.
• Sodium borate in sodium or potassium phosphate-dibasic solution 0.05 M of borate to 0.05 M phosphate.
• a first working solution is prepared consisting of two parts of the 40% urea solution combined with two parts of the 4% sodium dodecyl sulfate solution.
• a preferred alternate working solution consists of one part of the urea solution with three parts of the sodium dodecyl sulfate solution.
• one part of a said sodium dodecyl sulfate urea solution is mixed with one part of the boratephosphate buffer solution and buffered using sodium hydroxide to a pH of about 12.4.
• the second working solution comprises the saturated picric acid solution.
• four parts of the first working solution are mixed with one part of the saturated picric acid solution to provide a single alkaline picrate reagent.
• 0.01 to 2.0 ml of sample has been used with 0.2 to 25.0 ml of final mixed reagent.
• 0.1 to 0.2 ml of sample with 4.0 ml of final reagent is used.
• 4.0 ml of alkaline picrate reagent is introduced into a suitable test tube and pre-incubated at 37 Centrigrade for 3 to 5 minutes.
• 0.1 or 0.2 ml of sample is mixed into the reagent and incubation at 37 Centrigrade maintained for from to 30 minutes. Preferably, such incubation is maintained for minutes.
• the incubated solution then is introduced into a colorimeter or spectrophotometer against a blank and light absorption of the thusly formed creatinine picrate is read at 490 to 535 nm. Preferably, the reading is made at 500 nm. Then, one can calculate the value of unknown against primary aqueous standard or secondary protein-based standard run in conjunction with the unknown using the following formula:
• the alkaline picrate reagent can be buffered to within a pH range of l 1.0 to 13.5 by selective mixing of the buffer solution, to wit, the sodium borate in the sulfate solution as mentioned.
• Optical density measurements can be taken within the range of wavelengths statedv
• other modifications may occur to the skilled artisan relating to a particular material for mulation to utilize the essential teachings of the invention.
• other detergents which may be used are: sodium octyl sulfate. sodium tetradecyl sulfate, sodium heptadecyl sulfate. sodium cetyl sulfate.
• sodium myristyl sulfate sodium octadecyl sulfate, sodium oleyl sulfate, sodium tridecyl sulfate, potassium lauryl sulfate and dodecyl benzene sulfate.
• the analagous potassium or lithium salts are equally useful.
• the detergent may be characterized as an aralkane sulfate of sodium. potassium or lithium.
• a colorimetric process for the determination of creatinine in a biologic fluid sample containing proteins comprising,
• sample size of sample is maintained from 0.01 to 2.0 ml.
• Part A 6 tion of Part A is mixed with the solution of Part B to provide an alkaline-picrate reagent used in the creatinine determination.

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• Life Sciences & Earth Sciences (AREA)
• Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• Molecular Biology (AREA)
• Biomedical Technology (AREA)
• Chemical & Material Sciences (AREA)
• Hematology (AREA)
• Immunology (AREA)
• Urology & Nephrology (AREA)
• Cell Biology (AREA)
• Microbiology (AREA)
• Biotechnology (AREA)
• Food Science & Technology (AREA)
• Medicinal Chemistry (AREA)
• Physics & Mathematics (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• General Health & Medical Sciences (AREA)
• General Physics & Mathematics (AREA)
• Pathology (AREA)
• Investigating Or Analysing Biological Materials (AREA)

Priority Applications (13)

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Cited By (7)

Citations (3)

• 1974
  • 1974-03-04 US US447864A patent/US3894843A/en not_active Expired - Lifetime
  • 1974-12-18 NL NL7416476A patent/NL7416476A/xx unknown
  • 1974-12-25 IL IL46338A patent/IL46338A/en unknown
• 1975
  • 1975-01-08 BE BE6044885A patent/BE824205A/xx unknown
  • 1975-01-13 ZA ZA00750224A patent/ZA75224B/xx unknown
  • 1975-01-24 GB GB321475A patent/GB1445954A/en not_active Expired
  • 1975-01-24 ES ES434127A patent/ES434127A1/es not_active Expired
  • 1975-01-30 SE SE7501016A patent/SE7501016L/xx unknown
  • 1975-01-30 FR FR7502948A patent/FR2263515A1/fr not_active Withdrawn
  • 1975-01-31 JP JP50012630A patent/JPS50120897A/ja active Pending
  • 1975-01-31 CH CH127875A patent/CH594245A5/xx not_active IP Right Cessation
  • 1975-02-06 DE DE19752504994 patent/DE2504994A1/de active Pending

Patent Citations (3)

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