Methods and Compositions for Highly Sensitive Detection of Molecules

Abstract

Disclosed are methods, kits, and compositions for the highly sensitive detection of molecules. The methods, kits, and compositions are useful in determining concentrations of molecules in samples to levels of 1 femtomolar, 1 attomolar, or lower. The methods, kits, and compositions also allow the determination of concentration over a wide range, e.g., 7-log range, without need for sample dilution.

1 - 49 . (canceled) 
     
     
         50 . An analyzer system kit for detecting a concentration of a protein molecule in a sample, said kit 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 pump for moving said label in said capillary flow cell;   d) an interrogation space defined within said capillary flow cell for receiving electromagnetic radiation emitted from said electromagnetic source; and   e) an electromagnetic radiation detector operably connected to said interrogation space for measuring an electromagnetic characteristic of said fluorescent moiety;   wherein said fluorescent moiety is capable of emitting at least about 200 photons when stimulated by a laser emitting light at the excitation wavelength of the moiety that is focused on a spot not less than about 5 microns in diameter with a total energy directed at the spot by the laser is no more than about 15 microJoules.   
     
     
         51 . The analyzer system kit of  claim 50 , wherein said electromagnetic radiation source is a laser, and wherein said laser has a power output of at least about 3, 5, 10, or 20 mW. 
     
     
         52 . The analyzer system kit of  claim 50 , wherein said fluorescent moiety comprises a fluorescent molecule.