Abstract: Methods for harmonization of test results from a biological sample in a multiplexed biochemical assay, wherein presence and/or concentration of multiple biomarkers are determined at the same time in the same sample, making test results obtained in different laboratories comparable comprise: quantifying a presence or concentration of at least two different biomarkers in a biological sample and in a harmonization standard sample, independently in each sample, by means of a defined multiplexed biochemical assay implemented in a defined type of analytical instrument; receiving the test results from the samples into a computer-based decision engine for harmonization of test results from biological samples; and transforming the test results received from the biological sample, which includes transforming the test results from the harmonization standard sample into generalized units and adjusting the test results of the biological sample into the generalized units, GE.