Cromatest

In the Trinder reaction, glucose is oxidised to D-gluconate by glucose oxidase (GOD), with formation of hydrogen peroxide. In the presence of peroxidase (POD), phenol and 4-aminoantipyrine (4-AA) are condensed by hydrogen peroxide, forming a red quinoneimine proportional to the concentration of glucose in the sample.

In the Trinder reaction, glucose is oxidised to D-gluconate by glucose oxidase (GOD), with formation of hydrogen peroxide. In the presence of peroxidase (POD), phenol and 4-aminoantipyrine (4-AA) are condensed by hydrogen peroxide, forming a red quinoneimine proportional to the concentration of glucose in the sample.

In the Trinder reaction, glucose is oxidised to D-gluconate by glucose oxidase (GOD), with formation of hydrogen peroxide. In the presence of peroxidase (POD), phenol and 4-aminoantipyrine (4-AA) are condensed by hydrogen peroxide, forming a red quinoneimine proportional to the concentration of glucose in the sample.

In the Trinder reaction, glucose is oxidised to D-gluconate by glucose oxidase (GOD), with formation of hydrogen peroxide. In the presence of peroxidase (POD), phenol and 4-aminoantipyrine (4-AA) are condensed by hydrogen peroxide, forming a red quinoneimine proportional to the concentration of glucose in the sample.

This technique employs a separation method based on the selective precipitation of apoprotein-B-containing lipoproteins (VLDL, LDL and (a)Lpa) by the action of phosphotungstic acid/Cl2Mg, sedimentation of the precipitate by centrifugation and subsequent enzymatic analysis as residual cholesterol from the high-density lipoproteins (HDL) contained in the clear supernatant.

Hydrogen peroxide derived from the oxidase reaction is quantified by a Trinder-type reaction in which the chromogenic derivative HTIB and 4-aminoantipyrine (4-AA) condense in the presence of peroxidase (POD) to form a red quinonimine dye.

This technique employs a separation method based on the selective precipitation of apoprotein-B-containing lipoproteins (VLDL, LDL and (a)Lpa) by the action of phosphotungstic acid/Cl2Mg, sedimentation of the precipitate by centrifugation and subsequent enzymatic analysis as residual cholesterol from the high-density lipoproteins (HDL) contained in the clear supernatant.

This technique employs a separation method based on the selective precipitation of apoprotein-B-containing lipoproteins (VLDL, LDL and (a)Lpa) by the action of phosphotungstic acid/Cl2Mg, sedimentation of the precipitate by centrifugation and subsequent enzymatic analysis as residual cholesterol from the high-density lipoproteins (HDL) contained in the clear supernatant.

Creatine kinase (CK) catalyzes the reaction between creatine phosphate (CP) and adenosine 5'-diphosphate (ADP), forming creatine and adenosine 5'-triphosphate (ATP). The latter converts glucose to glucose-6-phosphate (G6P) in the presence of hexokinase (HK). G6P is oxidized to gluconate-6P in the presence of reduced nicotinamide adenine dinucleotide phosphate (NADP), catalyzed by glucose-6-phosphate dehydrogenase (G6PDH). The conversion is kinetically monitored at 340 nm through the increase in absorbance resulting from the reduction of NADP to NADPH, proportional to CK activity in the sample. The inclusion of N-acetylcysteine (NAC) in this method allows optimal enzyme activation.

Creatine kinase (CK) catalyzes the reaction between creatine phosphate (CP) and adenosine 5'-diphosphate (ADP), forming creatine and adenosine 5'-triphosphate (ATP). The latter converts glucose to glucose-6-phosphate (G6P) in the presence of hexokinase (HK). G6P is oxidized to gluconate-6P in the presence of reduced nicotinamide adenine dinucleotide phosphate (NADP), catalyzed by glucose-6-phosphate dehydrogenase (G6PDH). The conversion is kinetically monitored at 340 nm through the increase in absorbance resulting from the reduction of NADP to NADPH, proportional to CK activity in the sample. The inclusion of N-acetylcysteine (NAC) in this method allows optimal enzyme activation.

Creatine kinase (CK) catalyzes the reaction between creatine phosphate (CP) and adenosine 5'-diphosphate (ADP), forming creatine and adenosine 5'-triphosphate (ATP). The latter converts glucose to glucose-6-phosphate (G6P) in the presence of hexokinase (HK). G6P is oxidized to gluconate-6P in the presence of reduced nicotinamide adenine dinucleotide phosphate (NADP), catalyzed by glucose-6-phosphate dehydrogenase (G6PDH). The conversion is kinetically monitored at 340 nm through the increase in absorbance resulting from the reduction of NADP to NADPH, proportional to CK activity in the sample. The inclusion of N-acetylcysteine (NAC) in this method allows optimal enzyme activation.

The higher activity of CK in normal sera is due to the isoenzymes CK-MM and CK-MB present in muscle and cardiac tissues. CK-BB is usually present at very low concentrations. Both creatine kinase (CK) enzymes are dimers formed by the association of two muscle (M) and brain (B) subunits. Immunoinhibition with a specific antibody for both MM subunits and the individual unit of CK-MB allows the determination of the B subunit. The activity corresponding to half of CK-MB is measured through the increase in absorbance resulting from coupled reactions.