A quantitative method for determining tissue characteristics includes the steps of generating data for a dynamic optical curve over a period of time based on an optical property of a tissue, or portion thereof, that has been exposed to a biomarker and, based on the data, determining a value of a dynamic optical parameter. The value of the dynamic optical parameter is compared with at least one reference value of the dynamic optical parameter known to be linked to a structural or functional characteristic and/or the pathological status of the tissue. Based on the comparison, a structural or functional characteristic and/or the pathological status of the tissue, or portion thereof is determined. Data for dynamic optical curves may be generated for a plurality of tissue locations corresponding to a plurality of spatial image locations. The plurality of dynamic optical curves may be used to determine values of a dynamic optical parameter and a related tissue characteristic at a plurality of tissue locations. A computer readable medium holds computer program instructions for carrying out this method. Reference values can be calculated by measuring dynamic optical properties from known representative tissue samples. Preferred tissue samples include endothelial and cervical samples. Preferred methods involve diagnosing and/or grading neoplasia and/or HPV infection and/or calculating nuclear to cytoplasmic ratios of the cells in the tissue sample.