The determination of glucose levels is an essential process that involves either qualitative or quantitative analysis of glucose present in bodily fluids, such as blood or urine. The glucose oxidase and hexokinase methods are commonly used for this purpose. Additionally, the urine sugar test paper is a cost-effective and non-invasive way to qualitatively detect glucose in urine, and it's often used for preliminary screenings of diabetes. For immediate quantification of blood glucose levels, portable blood glucose meters are used, which are both convenient and accurate, and can be used at the patient's bedside.
1. Glucose oxidase method
The glucose oxidation reaction is facilitated by glucose oxidase, which leads to the production of hydrogen peroxide. Peroxidase then acts as a catalyst to combine hydrogen peroxide with a chromogenic oxygen receptor, resulting in the formation of a red compound. This particular compound exhibits its highest absorption peak at 505mm and the intensity of its absorption is directly proportional to the quantity of glucose present.
To determine the glucose concentration in a sample, follow these steps: first, combine the serum and enzyme phenol reagent. Ensure thorough mixing and create a suitable environment for the reaction. Next, measure the absorbance value of the resulting product at 505mm using a spectrophotometer that has been zero adjusted. Finally, retrieve the glucose concentration by either referencing a table or calculating it based on the photometric value obtained. Remember to accurately execute each step to obtain precise results.
2. Hexokinase method
(2) In the presence of hexokinase and magnesium ions, principle glucose undergoes a reaction with adenine adenosine triphosphate (ATP) to form glucose-6-phosphate. This glucose derivative, under the catalysis of glucose-6-phosphate dehydrogenase, reduces NADP+ to NADPH, which can be measured at 340nm. The amount of NADPH produced is directly proportional to the glucose content of the sample. This method therefore provides a reliable and accurate means of quantifying glucose levels in biological samples.
The automatic biochemical analyzer has the ability to detect the steps involved in the process. Once the sample is mixed with the appropriate enzyme mixing reagent, it can be introduced into the automatic biochemical analyzer. This analyzer calculates the rate of increase in absorbance and allows for the determination of glucose concentration in the sample. This can be achieved by referring to either a standard curve or a specific mathematical formula.
