Practice question

Relation between absorbance and percent transmittance follows logarithmic conversion: A = 2 - log10(%T), derived from A = -log10 T. Hence %T equals 100 multiplied by 10 raised to -A. Substituting values, absorbance zero corresponds to 100%, one to 10%, two to 1%, three to 0.1% transmittance. Each unit increase reduces transmitted light tenfold exponentially. At absorbance three only one thousandth of incident beam reaches detector, approaching stray light limit where noise dominates. Accurate quantitation therefore requires diluting samples to maintain absorbance within 0.1 to 1.5 linear range for reliable nucleic acid or protein estimation.