Clinical biochemical analysis requires the interaction of the signal from an assay reaction product with a sequence of optical, mechanical, electronic and computational subassemblies. Each of these components can introduce an uncertainty into the final precision of measurement. Contributions from uncertainties in the concentration of sample chromophore differ from standard models of detector response in absorbance measurements. A Beer's Law absorbance model predicts that relative errors in concentration decrease momotonically with increasing absorbance. The product of molar absorptivity, path length and chromophore concentration uncertainty characterizes this effect. Precision of concentration must be controlled according to the particular molar absorptivity and detector response of the instrument. Assay chemistry factors dominate at low absorbance values, making high precision difficult at low absorbance.

Date Published: 3 April 1995
PDF: 14 pages
Proc. SPIE 2386, Ultrasensitive Instrumentation for DNA Sequencing and Biochemical Diagnostics, (3 April 1995); doi: 10.1117/12.206018

Published in SPIE Proceedings Vol. 2386:
Ultrasensitive Instrumentation for DNA Sequencing and Biochemical Diagnostics
Gerald E. Cohn; Jeremy M. Lerner; Kevin J. Liddane; Alexander Scheeline; Steven A. Soper, Editor(s)