Urea

200

Substrates & Metabolites

Urea

Serum or heparinised plasma

R1: 2 x 16.7 mL;
R2: 1 x 8.5 mL,
Ready to use

Instructions for Use  |  Safety Data Sheet

For professional use only.

Urea is the product of metabolism with the highest nitrogen content deriving from protein catabolism in the human species and represents over 75% of protein nitrogen. Over 90% of Urea is secreted by the kidneys, while the gastrointestinal tract and the skin account for most of the remaining fraction. There are three factors which determine the plasma urea concentration: renal perfusion and amount of water secreted, rate of urea synthesis, and rate of glomerular filtration. Numerous increases in the plasmatic urea concentration are caused by a wide range of renal diseases. In children, protein catabolism is reduced due to the greater protein requirements necessary for growth, therefore the serum urea concentrations are lower compared to adults. Pregnant women show urea levels outside the normal range due to the greater protein requirements of the fetus, in addition to the renal hyperperfusion.

In the presence of urease, urea is hydrolysed into ammonium ions and carbon dioxide. In the presence of glutamate-dehydrogenase (GLDH), the ammonium ion produced reacts with α-ketoglutarate (α-KG) and NADH to form glutamate and NAD. The consumption of NADH over a given period, determined at λ 340 nm, is proportional to the Urea concentration in the test sample.
Urea + H2O --(Urease)--> 2NH3 + CO2
NH3 + α-KG + NADH --(GLDH)--> L-Glutamate + NAD

Store at 2-8°C; protect from direct light. When correctly stored, the reagent is stable up to the expiry date reported on the label. A slight variation in the composition of the components may occur between batches, but this has no effect on the test results. After opening, the vial R1 and R2 are stable 30 days if recapped immediately and protected from contamination, evaporation, direct light and stored at correct temperature.

Multicalibrator (R0300000006)
Normal control serum (R0400000006)
Pathological control serum (R0400000106)