Human serum glucose determination

Method-dependent measurements can be grouped by sector. For example, in the clinical fields there are cases where some higher order reference materials are required for IVD methods, such as for determination of glucose in human serum. It is also required of reference laboratories in specific measurement methods. These issues are now under the responsibility of JCTLM (Joint Committee on the Traceability of Laboratory Medicine of CCQM). CENAM has developed a reference material for glucose and cholesterol determination in human serum, and certified by IDMS, which is under review by JCTLM for the use by reference laboratories in any country applying a reference method. 

Go to http //chemistry.brookscole.com/skoogfac/. From the Chapter Resources menu, choose Web Works. Locate the Chapter 34 section, click on the link for NIST, and find the pages dealing with Standard Reference Materials (SRMs). Look under Health Care and Nutrition. Find the Clinical Laboratory Materials available as SRMs. Find the information on glucose in frozen human serum and look up the Certificate of Analysis. Determine the relative uncertainties (as defined by NIST) of the glucose concentrations in mg/dL for the three different levels available. 

Optoelectronic biosensors based on immobilized dyes have been developed for the determination of glucose, urea, penicillin, and human serum albumin (Lowe et al., 1983). Other promising approaches use immobilized luciferase or horseradish peroxidase to assay ATP or NADH or, when coupled with oxidases, to measure uric acid or cholesterol. These principles have not yet been generally accepted for use in routine analysis. Most probably, the first commercial optical biosensors will be those for immunological assays. 

Most amperometric detection relies on enzymatic activity. A biosensor based on encapsulated glucose oxidase within a sol-gel glass has been used to determine glucose in an electrolytic solution for intravenous administration and human serum samples. 

NIR spectral measurements of human skin stretch back to 1950s. Real trials for in vivo and in vitro NIR spectroscopic determination of biomedical components with chemometrics started in 1980s. There have been two major streams for NIR-chemometrics investigations on biomedical components. One is concerned with the quantitative analysis of various biomedical analytes in in vitro samples, especially in human serum, and the other is in vivo blood glucose measurement for possible application to clinical diagnosis. 

NIR Spectroscopic Determination of Human Serum Albumin, /-Globulin, and Glucose in a Control Serum Solution with SCMWPLS... 

Y. Lv, Z. Zhang, F. Chen, Chemiluminescence microflnidic system sensor on a chip for determination of glucose in human serum with immobilized reagents, Talanta 59 (3) (March 2003) 571-576. 

Based on these results, a simple and unique determination of 14 L-amino acids and glucose as substrates was developed. Thus, the calibration graph for a representative amino acid, L-phenylalanine was linear in the concentration range 1.0 x 10 6-2 x 10 8 M with a relative standard deviation of 5.78% and a correlation coefficient of 0.9974. The detection limit obtained was 1.05 X 10 8 M. In the case of glucose the calibration graph was linear in the concentration range 2.7 X 10 6-2.7 X 10 8 M with a relative standard deviation of 4.27% and a correlation coefficient of 0.9980. The detection limit was 2.7 X 10 8 M. The method was successfully applied to the determination of glucose in human blood serum. 

An error in an experimental measurement is defined as a deviation of an observed value from the true value. There are two types of errors, determinate and indeterminate. Determinate errors are those that can be controlled by the experimenter and are associated with malfunctioning equipment, improperly designed experiments, and variations in experimental conditions. These are sometimes called human errors because they can be corrected or at least partially alleviated by careful design and performance of the experiment. Indeterminate errors are those that are random and cannot be controlled by the experimenter. Specific examples of indeterminate errors are variations in radioactive counting and small differences in the successive measurements of glucose in a serum sample. 

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