Abstract: A method of increasing a concentration of an antigen of a respiratory virus is provided. The method includes preparing a sample containing a first concentration of the antigen; contacting the sample containing the first concentration of the antigen to a first material having a negatively-charged surface, thereby capturing an amount of the antigen with the first material; contacting a second material to the first material to transfer the antigen from the first material to the second material, the second material having an ionic strength sufficient to release the captured antigen from the first material into the second material; and obtaining a resulting solution containing the antigen in a second concentration. The second concentration of the antigen in the resulting solution is higher than the first concentration of the antigen in the sample. Numerous other aspects in accordance with this and other embodiments are provided.

Abstract: Microfluidic devices, method for making and using same are disclosed. The microfluidic device can be made by applying a reagent in liquid form into a sample treatment site within a substrate base. The substrate base has hydrophilic properties bordering a flow channel, and has an application site, the sample treatment site and an analytical site. The flow channel is sized and configured so as to draw a sample applied into the application site to the analytical site through the sample treatment site by capillary action. The reagent is freeze-dried within the sample treatment site.

Abstract: Devices and methods for the hook effect detection associated with analytes of interest in the conductance of one or more diagnostic assays, including, without limitation, immunoassays.

Abstract: Embodiments of the invention relate to a single-polarization fiber that may include a W-type refractive-index profile having a depressed region along an unguided principal axis of the fiber, and a quasi step-index profile along a guided principal axis of the fiber. The quasi step-index profile may have a depressed region with a radial extent at least twice that of the depressed region along the unguided axis.

Abstract: Embodiments of the invention relate to a single-polarization fiber that may include a W-type refractive-index profile having a depressed region along an unguided principal axis of the fiber, and a quasi step-index profile along a guided principal axis of the fiber. The quasi step-index profile may have a depressed region with a radial extent at least twice that of the depressed region along the unguided axis.