(299i) Novel Aspects of the Hydrodynamics of Particle-Laden Liquids: Example of a Successful Transient Flow Immunoassay (TrIA)

In medicine, measuring the amount of solid precipitate formed when antigens react with antibodies is a foundational principle used to conduct a wide variety of diagnostic tests.  Typically, the degree of precipitation of antigen-antibody complexes is determined by measuring the light scattered off the suspended solids. To obtain accurate measurements of the suspended solids, specialized light sources and detectors are required; thus dedicated and well-calibrated instruments are essential. Here we show that the amount of solids suspended in liquids can be determined using a novel aspect of the hydrodynamics of particle-laden liquids. Using our method, the amount of solids in a liquid can be determined with minute quantities of liquid (< 20 microliters) and short times (< 10 minutes) without the need for dedicated optics and instruments. As an example of a successful application, we conduct an immunoassay to determine the amount of total serum IgG, which is an antibody present in blood.