Cromatest

This method for the determination of total cholesterol in serum is based on the use of three enzymes: cholesterol esterase (CE), cholesterol oxidase (CO), and peroxidase (POD). In the presence of the latter, the mixture of phenol and 4-aminoantipyrine (4-AA) condenses due to hydrogen peroxide, forming a colored quinonimine proportional to the concentration of cholesterol in the sample.

This method for the determination of total cholesterol in serum is based on the use of three enzymes: cholesterol esterase (CE), cholesterol oxidase (CO), and peroxidase (POD). In the presence of the latter, the mixture of phenol and 4-aminoantipyrine (4-AA) condenses due to hydrogen peroxide, forming a colored quinonimine proportional to the concentration of cholesterol in the sample.

This method for the determination of total cholesterol in serum is based on the use of three enzymes: cholesterol esterase (CE), cholesterol oxidase (CO), and peroxidase (POD). In the presence of the latter, the mixture of phenol and 4-aminoantipyrine (4-AA) condenses due to hydrogen peroxide, forming a colored quinonimine proportional to the concentration of cholesterol in the sample.

This method for the determination of total cholesterol in serum is based on the use of three enzymes: cholesterol esterase (CE), cholesterol oxidase (CO), and peroxidase (POD). In the presence of the latter, the mixture of phenol and 4-aminoantipyrine (4-AA) condenses due to hydrogen peroxide, forming a colored quinonimine proportional to the concentration of cholesterol in the sample.

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.

Diazotized sulfanilic acid transforms bilirubin into colored azobilirubin, which is determined photometrically. Of the two fractions of bilirubin present in serum, bilirubin glucuronate and bilirubin free associated with albumin, only the first reacts directly, while the free bilirubin needs to be dissociated from the protein by an accelerator to react. Indirect bilirubin is calculated by the difference between total bilirubin (with accelerator) and direct bilirubin (without accelerator). The concepts of 'direct' and 'indirect' refer exclusively to the reaction characteristics in the presence or absence of accelerators or solubilizers and are only approximate equivalents to the two mentioned bilirubin fractions.

Diazotized sulfanilic acid transforms bilirubin into colored azobilirubin, which is determined photometrically. Of the two fractions of bilirubin present in serum, bilirubin glucuronate and bilirubin free associated with albumin, only the first reacts directly, while the free bilirubin needs to be dissociated from the protein by an accelerator to react. Indirect bilirubin is calculated by the difference between total bilirubin (with accelerator) and direct bilirubin (without accelerator). The concepts of 'direct' and 'indirect' refer exclusively to the reaction characteristics in the presence or absence of accelerators or solubilizers and are only approximate equivalents to the two mentioned bilirubin fractions.

Diazotized sulfanilic acid transforms bilirubin into colored azobilirubin, which is determined photometrically. Of the two fractions of bilirubin present in serum, bilirubin glucuronate and bilirubin free associated with albumin, only the first reacts directly, while the free bilirubin needs to be dissociated from the protein by an accelerator to react. Indirect bilirubin is calculated by the difference between total bilirubin (with accelerator) and direct bilirubin (without accelerator). The concepts of 'direct' and 'indirect' refer exclusively to the reaction characteristics in the presence or absence of accelerators or solubilizers and are only approximate equivalents to the two mentioned bilirubin fractions.

Diazotized sulfanilic acid transforms bilirubin into colored azobilirubin, which is determined photometrically. Of the two fractions of bilirubin present in serum, bilirubin glucuronate and bilirubin free associated with albumin, only the first reacts directly, while the free bilirubin needs to be dissociated from the protein by an accelerator to react. Indirect bilirubin is calculated by the difference between total bilirubin (with accelerator) and direct bilirubin (without accelerator). The concepts of 'direct' and 'indirect' refer exclusively to the reaction characteristics in the presence or absence of accelerators or solubilizers and are only approximate equivalents to the two mentioned bilirubin fractions.

Diazotized sulfanilic acid transforms bilirubin into colored azobilirubin, which is determined photometrically. Of the two fractions of bilirubin present in serum, bilirubin glucuronate and bilirubin free associated with albumin, only the first reacts directly, while the free bilirubin needs to be dissociated from the protein by an accelerator to react. Indirect bilirubin is calculated by the difference between total bilirubin (with accelerator) and direct bilirubin (without accelerator). The concepts of 'direct' and 'indirect' refer exclusively to the reaction characteristics in the presence or absence of accelerators or solubilizers and are only approximate equivalents to the two mentioned bilirubin fractions.

Diazotized sulfanilic acid transforms bilirubin into colored azobilirubin, which is determined photometrically. Of the two fractions of bilirubin present in serum, bilirubin glucuronate and bilirubin free associated with albumin, only the first reacts directly, while the free bilirubin needs to be dissociated from the protein by an accelerator to react. Indirect bilirubin is calculated by the difference between total bilirubin (with accelerator) and direct bilirubin (without accelerator). The concepts of 'direct' and 'indirect' refer exclusively to the reaction characteristics in the presence or absence of accelerators or solubilizers and are only approximate equivalents to the two mentioned bilirubin fractions.