Abstract: The present disclosure is directed to a thin-film element that enables analytes to be analyzed on separate surfaces. In an example, a thin-film element includes a first layer for processing a fluid sample to generate a first analyte and a second analyte. The thin-film element also includes a second layer configured to be impermeable to the first analyte to enable the first analyte to be retained by the first layer and permeable to the second analyte to enable the second analyte to pass through the second layer. The thin-film element further includes a third layer configured to retain the second analyte. The second layer includes a first reflective surface and a second reflective surface to provide reflectance signals indicative of analytes present in the first and third layers to sensors located on opposite sides of the thin-film element.

Abstract: An antigen with an increased half-life is provided for the formulation of more stable and consistent clinical diagnostic immunoassay controls and calibrators. An antigen analogue comprises a first and a second polypeptide which is identical or similar to corresponding terminal amino acid sequences of an antigen. The first and second polypeptides are connected with a PEG chain. Also provided are methods of calibrating assays using a compound disclosed herein.

Abstract: The present disclosure is directed to a thin-film element that enables analytes to be analyzed on separate surfaces. In an example, a thin-film element includes a first layer for processing a fluid sample to generate a first analyte and a second analyte. The thin-film element also includes a second layer configured to be impermeable to the first analyte to enable the first analyte to be retained by the first layer and permeable to the second analyte to enable the second analyte to pass through the second layer. The thin-film element further includes a third layer configured to retain the second analyte. The second layer includes a first reflective surface and a second reflective surface to provide reflectance signals indicative of analytes present in the first and third layers to sensors located on opposite sides of the thin-film element.