SPINREACT products

Bilirubin is converted to colored azobilirubin by diazotized sulfanilic acid and measured photometrically. Of the two fractions presents in serum, bilirubin-glucuronide and free bilirubin loosely bound to albumin, only the former reacts directly in aqueous solution (bilirubin direct), while free bilirubin requires solubilization with caffeine to react (bilirubin indirect). In the determination of indirect bilirubin the direct is also determined, the results correspond to total bilirubin. The intensity of the color formed is proportional to the bilirubin concentration in the sample.

Albumin in the presence of bromocresol green at a slightly acid pH, produces a colour change of the indicator from yellow-green to - green-blue. The intensity of the color formed is proportionalto the albumin concentration in the sample.

Bilirubin (both conjugated and unconjugated) couples with the diazo reagent in the presence of a surfactant to form azobilirubin. The intensity of color formed is proportional to the bilirubin concentration in the sample tested. The increase of absorbance at 546 nm is directly proportional to the total bilirubin concentration.

The assay is based on the reaction of creatinine with sodium picrate as described by Jaffé. Creatinine reacts with alkaline picrate forming a red complex. The time interval chosen for measurements avoids interferences from other serum constituents. The intensity of the color formed is proportional to the creatinine concentration in the sample.

Diluent is a buffer solution used to dilute blood and prevent cells agglutination. With correct osmotic pressure, ion pressure and the electric conductivity, it can maintain the integrality and original volume of the blood cells.