Enzymatic / NAD+ - NADH
This kinetic enzymatic method is based on the oxidation of ß-hydroxybutarate to acetoacetate by the enzyme ß-hydroxybutarate dehydrogenase. Concomitant with this oxidation the cofactor NAD+ is reduced to NADH. The change in absorbance at 340 nm can be directly correlated with the ß-hydroxybutyrate concentration.

Vanadate oxidation
The bilirubin is oxidized by vanadate at about pH 3 to produce biliverdin. In the presence of detergent and vanadate, conjugated (direct) bilirubin is oxidized. This oxidation reaction causes a decrease in the optical density of the yellow color, which is specific to bilirubin. The decrease in optical density at 451/545 nm is proportional to the direct bilirubin concentration in the sample. The concentration is measured as an endpoint reaction.

(Metoden tatt i bruk: 15/8-07)

Tietz Fundamentals of Clinical Chemistry. 5th ed. Burtis CA, Ashwood ER, eds. Philadelphia, PA: WB Saunders Company; 2001:605.

Young DS. Effects of Drugs on Clinical Laboratory Tests. 3rd ed. Washington: AACC Press (1990).

Clinical and Laboratory Standards Institute (formerly NCCLS). Evaluation of Precision Performance of Quantitative Measurement Methods; Approved Guideline - Second Edition. Wayne, PA: Clinical and Laboratory Standards Institute; 2004. NCCLS Document EP05-A2.

Tietz NW. Clinical Guide to Laboratory Tests. 3rd ed. Philadelphia, PA: WB Saunders Company; 1995:88-91.

Study Group on Bilirubin for the Committee on Standards of the American
Association for Clinical Chemistry and the National Reference System for the Clinical Laboratory. NCCLS; Dec. 1986.

Vanadate oxidation
The bilirubin is oxidized by vanadate at about pH 3 to produce biliverdin. In the presence of the detergent and the vanadate, both conjugated (direct) and unconjugated bilirubin are oxidized. This oxidation reaction causes the decrease in the optical density of the yellow color, which is specific to bilirubin. The decrease in optical density at 451 nm is proportional to the total bilirubin concentration in the sample.

(Metoden tatt i bruk: 5/1-06)

Canine TLI is a solidphase, enzyme-labeled, chemiluminescent immunometric assay.
For detailed description: IMMULITE® 2000; Principles of operation

Williams DA, Batt RM. Diagnosis of canine exocrine pancreatic insufficiency by the assay of serum trypsin-like immunoreactivity. J Small Anim Practice 1983;24:582-8.

Williams DA. New tests of pancreatic and small intestinal function. Compendium on Continuing Education for the Practicing Veterinarian 1987;9:1167-74.

Williams DA. Exocrine pancreatic disease. In: Ettinger SJ, editor. Textbook of veterinary internal medicine: Diseases of the dog and cat. 2nd ed. Philadelphia: W.B. Saunders, 1989: 1528-54.

Williams DA, Batt RM. Exocrine pancreatic insufficiency diagnosed byradioimmunoassay of serum trypsin-like immunoreactivity in a dog with a normal BT-PABA test result. J Am Anim Hosp Assoc 1986;22:671-74.

Williams DA, Batt RM. Sensitivity and specificity of radioimmunoasay of
serum trypsin-like immunoreactivity for the diagnosis of canine exocrine pancreatic insufficiency. J Am Anim Hosp Assoc 1988;192:195-201.

Canine TSH is a solidphase, two-site chemiluminescent immunometric assay.
For detailed description: IMMULITE® 2000; Principles of operation

Ferguson DC. Update on diagnosis of canine hypothyroidism. Vet Clin North Am 1994;24:515-39.

Kemppainen RJ, Clark TP. Etiopathogenesis of canine hypothyroidism. Vet Clin North Am 1994;24:467-76.

IMMULITE 2000 Cortisol is a solid-phase,competitive chemiluminescent enzyme immunoassay.
For detailed description: IMMULITE® 2000; Principles of operation

Farmer R, Pierce C. Plasma cortisol determinations: radioimmunoassay andcompetitive protein binding compared. Clin Chem 1974; 20:411.

Kowalski A, Paul W. A simple extraction procedure for the determination offree (unconjugated) cortisol in urine by radioimmunoassay. Clin Chem 1976;25:1152.

Wilson JD, Foster DW, editors. Williams textbook of endocrinology. 7thed. Philadelphia: W.B. Saunders, 1985

The CRP method is a polyethylene glycol (PEG) enhanced immunoturbidimetric assay. Sample is reacted with specific antiserum to form a precipitate that is measured turbidimetrically at 340 nm. By constructing a standard curve from the absorbance of standards, concentration can be determined.

Kjelgaard-Hansen M., Jensen A.L., Kristensen A.T. 2003 Evaluation of a commercially available human C-reactive protein (CRP) turbidometric immunoassay for determination of canine serum CRP concentration. Vet Clin Pathol 32:81-87.

Enzymatic – colorimetric
This enzymatic method relies upon the acylation of coenzyme A(CoA) by the fatty acids in the presence of added acyl-CoA synthetase (ACS). The acyl-CoA produced is oxidized by added acyl-CoA oxidase (ACOD) with the generation of hydrogen peroxide. Hydrogen peroxide, in the presence of peroxidase (POD) permits the oxidative condensation of 3-methyl-N-ethyl-N-(b-hydroxyethyl)-aniline (MEHA) with 4-aminoantipyrine to form a purple color which can be measured at 545nm.

Enzymatic amplification / Thio-NAD – Thio-NADH
In the presence of Thio-NAD, the enzyme 3-α hydroxysteroid dehydrogenase (3-α HSD) converts bile acids to 3-keto steroids and Thio-NADH. The reaction is reversible and 3-α HSD can convert 3-keto steroids and Thio-NADH to bile acids and Thio-NAD. In the presence of excess NADH, the enzyme cycling occurs efficiently and the rate of formation of Thio-NADH is determined by measuring specific change of absorbance at 410nm.

Modified IFCC
In the reaction with synthetic substrate (L-γ-glutamyl-3-carboxy-4-nitroanilide), glycylglycine acts as an acceptor for the gamma-glutamyl residue and 5-amino-2-nitro-benzoate (ANB) is liberated. The liberated product has an absorption maximum near 400 nm; the rate of formation is measured photometrically at 410 nm as a zero-order kinetic assay.

The Reanalyser is measuring GFR by computerized analysis of the contrast medium (non-radioactive iodinate) content of plasma samples. Reanalyser is based on the x-ray fluorescence technique.

DGKC / NADH - NAD+
This is an optimised standard method according to the recommendations of the Deutsche Gesellschaft für Klinische Chemie (DGKC). This procedure measures the non-specific creep. As NADH is oxidised, the decrease in the absorbance is measured at 340nm and is proportional to the GD activity.