PIFA^® technology represents a "rethinking" of an entire rapid diagnostics problem, yielding a new solution to many of the problems intrinsic to older technologies such as agglutination and membrane immunoassays. PIFA^® technology is based on the principles of the selective filtration of microparticles in response to antibody/antigen binding.

In practice, the technology involves combining a test sample (blood, serum, urine or saliva) with a reagent which consists of dyed microparticles coated with an antigen or antibody. Test samples containing corresponding antigens or antibodies (positive samples) will cause a complex inter-linked matrix of micro particles to form. Once the reagent has reacted with the sample, the mixture is introduced onto a membrane device. As the mixture flows through this device, membranes separate matrixed from nonmatrixed particles. These membranes, which are laminated together in a series, provide control of pore size, density and liquid fluidics. Larger matrixed particles can be efficiently filtered and separated from the rest of the reaction mixture, and are prevented from passing into the results window of the device.

Conversely, monodispersed particles are smaller and can penetrate the controlled pore membranes and migrate into the inner results window. This ability to separate particles and matrices allow for optimal coating of the microparticles, which in turn increases overall performance.

Please visit the PIFA^® Heparin/PF4 Rapid Assay Product section for more information on how this technology is currently being applied.