The results of the blood glucose determination using the glucose oxidase reaction showed a very high coefficient of variations, standard deviations, and variances. These are measures of the precision and ultimately, accuracy of the technique in measuring blood glucose. Although this technique has been used in the clinical settings for a long time, the results showed that a high degree of skill is required in conducting the assays. Being a colorimetric determination, there are many sources of error.
The first source would definitely be human error. Skill and experience is required in handling the pipettes, especially if the pipettes are not robotics-type and have not been calibrated. Errors are magnified especially when dealing with small concentrations, like the case here. Second source of errors would be the standards used. If standard chemicals or solutions are not freshly prepared, then errors in measurements are bound to happen. The structural form of the standard is also important.
Some glucose oxidases are specific for certain glucose anomers, and the amount of other anomers present in the solution cannot be measured. Validation of the results can be performed by comparing the values obtained using the glucose oxidase method with the other home kits that make use of strips, meters and the capillary methods. The glucose oxidase method, although theoretically more accurate compared to the others, requires a relatively larger amount of blood sample, which can be a disadvantage to those who have to continuously monitor their blood sugar several times a day every day.
References American Asociation for Clinical Chemistry 2009, ‘Glucose’. Lab Tests Online Organization. Retrieved May 18, 2009 from http://www. labtestsonline. org/understanding/analytes/glucose/test. html. Diabetes Research in Children Network (DirecNet) Study Group 2002, ‘FreeStyle Navigator™ Continuous Glucose Monitoring System Use in Children with Type 1 Diabetes: Results of a Pilot Trial’, Pediatrics, vol. 109, no. 2, pp. 347-349.
Mathews, C. K. , & Van Holde, K. 1996, Biochemistry (Second ed. ). The Benjamin Cummings Publishing Company, Inc. Menlo Park. Rea, C. 200, ‘Diabetes health center: blood glucose’. WebMD LLC. Retrieved May 17, 2009 from: http://diabetes. webmd. com/blood-glucose. Seibel, J. 2009, ‘Diabetes Guide: How to test your blood sugar with diabetes’, WebMD LLC. Retrieved May 17, 2009 from http://diabetes. webmd. com/guide/how-test-blood-glucose.