The FIDA technology quantifies and characterises protein behaviour in complex samples like plasma and serum. Works with molecules and particles ranging 0,5-1000 nm. Offers highly reproducible in-solution data complementary to other biophysics technologies but in an automated and minimal assay design format. Rapid assay development, minimal sample preparation, nanoliter sample consumption. Avoid assumptions with the first principle, absolute measurement of a biomolecules size and interactions.