Abstract: Methods for determining and/or quantifying one or more analytes in fluids are generally provided. In some embodiments, a method comprises introducing or exposing a plurality of conjugated capture structures and a plurality of metal-containing (e.g., silver) conjugated particles to a fluid comprising the analyte such that the analyte binds with both a capture structure and a metal-containing (e.g., silver) particle to form a bound complex. The bound complex may then be subjected to conditions (e.g., electrochemical conditions) that allow quantification of the analyte based on the amount of metal-containing particles present. The methods described herein may be useful for determining and quantifying relatively low concentrations of analytes present in a patient sample (e.g., a droplet of whole blood).

Abstract: The invention provides compositions and methods of use thereof for labeling peptide and proteins in vitro or in vivo. The methods described herein employ lipoic acid ligase or mutants thereof, and lipoic acid analogs recognized by lipoic acid ligase and lipoic acid ligase mutants.

Abstract: The invention provides compositions and methods of use thereof for labeling peptide and proteins in vitro or in vivo. The methods described herein employ lipoic acid ligase or mutants thereof, and lipoic acid analogs recognized by lipoic acid ligase and lipoic acid ligase mutants.

Abstract: The invention provides compositions and methods of use thereof for labeling peptide and proteins in vitro or in vivo. The methods described herein employ lipoic acid ligase or mutants thereof, and lipoic acid analogs recognized by lipoic acid ligase and lipoic acid ligase mutants.

Abstract: The invention provides compositions and methods of use thereof for labeling peptide and proteins in vitro or in vivo. The methods described herein employ lipoic acid ligase or mutants thereof, and lipoic acid analogs recognized by lipoic acid ligase and lipoic acid ligase mutants.