Assay Dynamic Range
The range of the assay is between 1.9 - 5000 pg/mL.
The following materials have been evaluated for cross reactivity. The percentage indicates cross reactivity at 50% displacement compared to Testosterone.
The lowest analytical detectable level of testosterone that can be distinguished from the Zero Standard is 1.9 pg/mL at the 95 % confidence limit. The lowest functional sensitivity of 7.1 pg/mL at the 95% confidence limit was obtained.
The intra-assay variation was determined by 20 replicate measurements of 5 saliva samples within one run. The withinassay variability is shown below:
The inter-assay (between-run) variation was determined by duplicate measurements of 5 saliva samples over 10 days.
The Inter-Lot (between-lot) variation was determined by triplicate measurements of five saliva samples in three different kit lots. The between lot variability is shown below:
Recovery of the CD ELISA was determined by adding increasing amounts of the analyte to six different saliva samples containing different amounts of endogenous analyte. Each sample (native and spiked) was assayed and analyte concentrations of the samples were calculated from the standard curve. The percentage recoveries were determined by comparing expected and measured values of the samples
Six saliva samples containing different amounts of analyte were serially diluted with zero standard and assayed with the CD ELISA. Three native samples were serially diluted, and 3 samples were spiked with testosterone and then serially diluted up to 1:128. The percentage recovery was calculated by comparing the expected and measured values for testosterone. An assay linearity of 7.1 - 4500 pg/mL has been identified as the usable range. Samples above this range must be diluted and re-run.
A study was performed that evaluated saliva samples from 99 male and female subjects ages 20 to 70 years. The saliva samples were run in duplicate on the test and a commercially available LIA method to determine the concentration of free Testosterone in the samples. A correlation of 0.904 and regression formula of y = 0.9251x - 7.4369 was obtained versus this method. Another study was performed to further evaluate the substantial equivalence of the Testosterone to the LIA saliva test. The concentration of testosterone in 81 additional saliva samples collected from 40 - 65 year old men and women was determined using testosterone kit and the other method. From this study an R2 = 0.9866 was obtained with the following regression.