Comparison of Glucose Measurements
Various glucose concentrations prepared in aMEM basal medium were detected by several commercial systems, including Std 1 and 2, ELISA, and GlucCell glucose meter. The results shown in Figure 1 illustrate that the accuracy of glucose measured by GlucCell was as good as that by Std 1 method and better than that by Std 2 and the ELISA enzymatic method. However, all results are within 15% accuracy range, which is generally considered acceptable for glucose measurement in cell cultures.
Figure 2 shows the comparison of the GlucCell measurement with other commercially available blood glucose meters. Results indicate that only GlucCell can be adopted for the glucose measurement in cell cultures, even though all of them were designed based on the same principle and methodology. This is primarily due to the difference of calibration procedures applied in different sample environment for its specific application. GlucCell was specifically calibrated and designed for cell culture application.
Figures 3 and 4 show the effect of various commercial media and FBS concentrations on the GlucCell glucose measurement and the Std 1 method. Results show that there is no noticeable effect of medium and FBS on measurement of glucose concentration. Results indicate that there is no apparent effect of the presence of CHO cells in the sample medium on the glucose measurement by both GlucCell meter and the Std 1 method. All these results confirm that GlucCell is as accurate as the Std 1 method.
Consistency of GlucCell measurements were evaluated with triplicate assays on each concentration. The consistency was determined by a value of CV that was defined as (SD/average) x 100%. Results show that all CV% values are below 4%.
Accuracy was evaluated with triplicate assays on samples with various known glucose concentrations. The accuracy was determined by percent recovery, defined as (average/target) x 100%. Results are greater than 90%.
Linearity was evaluated with assays on five series dilution of a sample medium with known glucose concentration of 564 mg/dL.
GlucCell glucose meter was developed through modification of a commercial blood glucose meter that was designed specifically for glucose monitoring for diabetes patients. GlucCell meter has been shown to be as accurate as the two most commonly used biochemical analyzers for glucose measurement in cell cultures. In reference to Std 1 measurement, there was no noticeable effect of various culture media, FBS, or cells on the measurement by GlucCell. The consistency, accuracy, and linearity of measurement using GlucCell meter were also excellent.
The cost of the device and consumable items, as well as the time, sample size, and labor required are favorable to the use of GlucCell over other commonly used devices. GlucCell meter provides a simple, accurate, and economical alternative for glucose measurement in cell cultures.