Non-luminescent substrate

Abstract

A substantially non-reflective, low or non-fluorescing substrate comprising a phase-inversion support and a plurality of opaque solids that are substantially chemically non-reactive with the phase inversion support and of a size sufficient to be partially or completely contained within, or intimately bound to, the phase inversion support. Methods of making and using the substantially non-reflective, low or non-fluorescing substrate are also disclosed.

1 - 25 . (canceled)  
     
     
         26 . An assay in which the presence or quantity of an analyte is being detected by fluorescence at an emission waveband of light that results from the excitation of a fluorescent signal label on a polyamide support by a excitation waveband of light, the assay comprising: 
 a polyamide support; and    a plurality of opaque solids incorporated into the polyamide support, said opaque solids being substantially chemically non-reactive with the polyamide support and a size sufficient to be partially or completely within, or irreversibly bound, to the polyamide support, and quenching fluorescence due to the polyamide substrate at the excitation waveband or emission waveband, or both.    
     
     
         27 . The assay as recited in  claim 26  wherein the polyamide support is in the form of a membrane.  
     
     
         28 . The assay as recited in  claim 26  wherein the opaque solids are carbon particles.  
     
     
         29 . The assay as recited in  claim 28  wherein the carbon particles are less than 5 microns in size.  
     
     
         30 . The assay as recited in  claim 29  wherein the carbon particles are substantially uniformly distributed throughout the polyamide support.  
     
     
         31 . The assay as recited in  claim 28  wherein the carbon particles are partially incorporated into the polyamide support.  
     
     
         32 . The assay as recited in  claim 28  wherein the carbon particles are substantially wholly incorporated into the polyamide support.  
     
     
         33 . The assay as recited in  claim 28  wherein the substrate is charge-modified.  
     
     
         34 . A method for preparing a substrate comprising a polyamide support irreversibly associated with opaque solids, such that substantially all of the polyamide surfaces are chemically and functionally available for binding of analyte; said method comprising the steps of: 
 formulating a casting dope comprising a solvent, one or more non-solvents, the opaque solids, and polyamide(s);    mixing and blending the casting dope to cause dissolution of the polyamide and opaque solids;    producing an opaque solids-filled phase inversion of casting dope;    casting a thin portion of the opaque solids-filled phase inversion casting dope;    quenching the cast portion of the opaque solids-filled phase inversion casting dope to form a substrate; and    drying the substrate.    
     
     
         35 . The method of  claim 34  wherein the opaque solids are carbon particles.  
     
     
         36 . The method of  claim 35  wherein the carbon particles are less than 5 microns in size.  
     
     
         37 . The method of  claim 35  wherein the carbon particles are substantially uniformly distributed throughout the polyamide support.  
     
     
         38 . The method of  claim 35  wherein the carbon particles are partially incorporated into the polyamide support.  
     
     
         39 . The method of  claim 35  wherein the carbon particles are substantially wholly incorporated into the polyamide support.  
     
     
         40 . The method of  claim 34  wherein the polyamide support is charge-modified.  
     
     
         41 - 57 . (canceled)  
     
     
         58 . A method for preparing a substrate comprising the acts of: 
 formulating a dope comprising a solvent, at least one non-solvent, opaque solids and at least one phase-inversion polyamide;    mixing and blending the dope to cause dissolution of the polyamide and opaque solids in the dope; and    producing an opaque solids-filled phase inversion membrane from the dope.    
     
     
         59 . The method of  claim 58  wherein the membrane producing act further comprises the acts of: 
 casting the dope;    quenching the opaque solids-filled phase inversion dope to form a substrate; and    drying the substrate.    
     
     
         60 . The method of  claim 59  wherein the membrane producing act further comprises the acts of: 
 irreversibly associating the membrane with the opaque solids such that substantially all of the membrane surfaces are chemically and functionally available for binding of analyte.    
     
     
         61 - 62 . (canceled)