Patent ID: 8685711
Filing Date: 2014-04-01
Classification: G01N

Abstract:
1. A system for detecting a single protein molecule in a sample, the system comprising an analyzer and at least one label comprising a fluorescent moiety and a binding partner for said protein molecule, and wherein said analyzer comprises: a) an electromagnetic radiation source for stimulating said fluorescent moiety, b) a capillary flow cell for passing said label; c) a source of motive force of moving said label in said capillary flow cell; d) an interrogation space within said capillary flow cell for receiving electromagnetic radiation emitted from said electromagnetic radiation source, wherein the interrogation space is defined by the focused spot of a beam from the electromagnetic radiation source wherein the spot has a diameter of 1-10 microns; and e) an electromagnetic radiation detector operably connected to said interrogation space for measuring an electromagnetic characteristic of said stimulated fluorescent moiety; wherein said fluorescent moiety emits at least about 200 photons when stimulated at the excitation wavelength of the moiety and the total energy directed at the interrogation space by the electromagnetic radiation source is no more than about 15 micro Joules.