Practice question
Question
Which formula relates absorbance (A) to transmittance (T)?
Explanation
Transmittance represents fraction of incident light passing through sample, defined as T = I/I0 ranging from zero to one, percent transmittance as T×100. Absorbance quantifies light retained by chromophores and is defined logarithmically to linearize exponential attenuation for quantitative analysis. Derivation from Beer-Lambert law gives A = -log10 T = log10(1/T) = log10(I0/I). This logarithmic inverse relationship converts exponential light loss into linear scale for concentration plots. At 100% transmittance absorbance zero; at 10% transmittance absorbance one. This conversion enables accurate determination of DNA, RNA and protein concentration.