Principles of the Reaction
The Synermed Triglycerides reagent system employs the enzymes lipase, glycerol kinase, glycerophosphate oxidase, and peroxidase and measures the formation of hydrogen peroxide. The reaction proceeds to a blue color which is measured spectrophotometrically at 660 nm, thus virtually eliminating chromatic interferences from hemoglobin, bilirubin and lipemia.
Triglycerides are hydrolyzed by lipase to glycerol and free fatty acids.
triglycerides -> glycerol + fatty acids
The glycerol formed reacts with adenosine-5'-triphosphate [ATP] in the presence of glycerol kinase [GK] to form adenosine-5'-diphosphate [ADP] and glycerol-1-phosphate [G-1-P].
glycerol + ATP -> G-1-P + ADP
Glycerol-1-phosphate is then oxidized by glycerophosphate oxidase [GPO] to Dihydroxyacetone phosphate [DHP] and hydrogen peroxide [H2O2].
G-1-P + O2 -> DHP + H2O2
The hydrogen peroxide reacts with the Synermed chromogen in the presence of peroxidase [POD] to form a blue azo dye which is quantitated between 630 and 660 nm.
Most applications of this procedure have been found to be linear to at least 10 mmol/L (870 mg/dL) triglycerides.
Signal to Noise Enhancement
The signal to noise enhancement of the Synermed® triglycerides method is due both to the elimination of noise from serum chromatic substances and to increased signal due to the improved sensitivity of the chromophore.
Because the lipase used in enzymatic methods clears lipemic turbidity, lipemia has not been a common problem in triglycerides assay. However, the accurate detection of serum glycerol blanks has been severely affected by the triglycerides because of turbidity.
Bilirubin and hemoglobin are responsible for most chromatic interferences in un-blanked triglycerides assay. The Synermed triglycerides assay is free of all serum chromatic interference.
The normal range for triglycerides in serum for fasting individuals is reported to be 0.3-1.5 mmol/L (30-135 mg/dL).
Special Performance Characteristics
- The Synermed triglycerides methodology was correlated to a widely accepted enzymatic method. The calculated linear regression on samples ranging from approximately 0.5 -6 mmol/L (50-500 mg/dL) with Synermed on the Y-axis was: Y = 1.02X + 0.09 mmol/L (8mg/dL) with a correlation coefficient of 0.999.
- The sensitivity of the procedure is such that an absorbance change of 0.001 will detect as little as 0.017 mmol/L (1.5 mg/dL) triglycerides.
- The average within run precision of the method was determined by assaying samples of quality control material at two levels of triglycerides concentration using an automated analyzer which provided the following results:
|<1.2 mmol/L (105 mg/dL)
|<2.7 mmol/L (236 mg/dL)
- The run to run reproducibility of the method as applied to an automated analyzer was determined from the values obtained by 5 replicate analyses of quality control material assayed over a 22 batch period. The following results were obtained:
|1.1 mmol/L (96 mg/dL)
|2.8 mmol/L (245 mg/dL)
Product Packaging and Storage
||Package Volume (mL)
||2x100 mL reconstituted
||6x100 mL reconstituted
||6x500 mL reconstituted
||1x55mL + 1 powder filled wedge