A technique is described for quantitating biological indicators, such as viral load, using interferometric interactions such as quantum resonance interferometry. A diffusion curve for the biological indicator of interest is generated from at least two measurements from a patient sample. In some embodiments, the patient samples are in the form of a microarray output pattern to which the patient sample has been applied. After the diffusion curve has been generated, subsequent patient samples are mapped to the diffusion curve to provide a quantitative measure of the biological indicator of interest.