The system was then allowed to stabilize for 10 minutes to acquire the absorbance unit
. The absorbance unit
(AU) of UV-Vis spectrum of clear and contaminant-free (particular matter-free) distilled water was 0.1 (Figure 5).
Spectral units are absorbance coefficient, calculated as optical extinction in absorbance units
(AU) at 532 nm divided by sample thickness (mm), relative to off-resonance extinction at 800 nm.
While the corrections are at most 0.004 absorbance units
in the extreme case, this is an important factor and a potential source of error.
The cut-off value for a positive result on ELISA was established at 0.188 absorbance units
, which corresponded to 2 standard deviations above the mean value obtained for the 25 healthy controls.
The solution extends the upper linearity level from two to typically six absorbance units
. This allows injection of 3x more sample while also reducing detector noise by 10x.
y = a + b C , where C so concentration of analyte (mg/ ml) a and y are absorbance units
. (Calculated from five determinations).
Results are expressed as relative absorbance units
Simple descriptive statistics for the population were mean 0.385 AU (absorbance units
), median 0.359AU, skewness 0.874, and kurtosis 1.044.
Typically this constant value was less than 0.005 absorbance units
(AU), and it was interpreted as scattering from larger impurities in the sample.
Median serum IMA levels were 44.80 absorbance units
in the DRP group and 40.15 absorbance units
in the control group (P = 0.031).