Device for detection of vitamin d metabolites

Abstract

The present invention provides methods, devices, and compositions to rapidly detect analytes, including small analytes, using a lateral flow device. Described herein is such a lateral flow device that can detect and quantify vitamin D in a whole blood, serum, or plasma sample by employing a sandwich-based immunoassay.

1 .- 39 . (canceled) 
     
     
         40 . A method for quantifying one or more vitamin D levels in a biological sample using a test device configured to perform a binding assay, said method comprising:
 (a) contacting said biological sample to said test device;   (b) subjecting said biological sample to said binding assay that utilizes a reaction mixture comprising a complex formed by: (i) a vitamin D binding agent; and (ii) one or more vitamin D molecules;   (c) further exposing said complex to a detection agent that binds to an epitope that is formed by complexing said vitamin D binding agent with said one or more vitamin D binding molecules,   wherein said binding assay has a sensitivity of detection in said biological sample that is comparable to that of liquid chromatography-tandem mass spectrometry,   thereby quantifying said one or more vitamin D levels in said biological sample.   
     
     
         41 . The method of  claim 40 , wherein said quantifying comprises classifying said biological sample as having a sufficient, an insufficient, or a deficient level of said one or more vitamin D molecules. 
     
     
         42 . The method of  claim 41 , wherein said sufficient level is at least about 30 ng/mL. 
     
     
         43 . The method of  claim 41 , wherein said insufficient level is at least about 10 ng/mL and less than about 30 ng/mL. 
     
     
         44 . The method of  claim 41 , wherein said deficient level is less than about 10 ng/mL. 
     
     
         45 . The method of  claim 40 , wherein said biological sample is selected from the group consisting of: whole blood, serum, plasma, urine, saliva, ocular fluid, spinal fluid, and perspiration. 
     
     
         46 . The method of  claim 40 , wherein said detection agent exhibits a higher binding affinity to said complex than said vitamin D binding agent. 
     
     
         47 . The method of  claim 40 , wherein said detection agent comprises a scFv, VH, Fab, or (Fab)2 binding unit. 
     
     
         48 . The method of  claim 40 , wherein said one or more vitamin D molecules are selected from the group consisting of: 25-hydroxyvitamin D 2 , 25-hydroxyvitamin D 3 , 25-hydroxyvitamin D 4 , 25-hydroxyvitamin D 5 , 1,25-hydroxyvitamin D 3 , and any combination thereof. 
     
     
         49 . The method of  claim 40 , wherein said one or more vitamin D molecules are selected from the group consisting of 25-hydroxyvitamin D 2  and 25-hydroxyvitamin D 3 . 
     
     
         50 . The method of  claim 40 , wherein said one or more vitamin D molecules are 25-hydroxyvitamin D 2  and 25-hydroxyvitamin D 3 . 
     
     
         51 . The method of  claim 40 , wherein said one or more vitamin D molecules consist of 25-hydroxyvitamin D 2 . 
     
     
         52 . The method of  claim 40 , wherein said one or more vitamin D molecules consist of 25-hydroxyvitamin D 3 . 
     
     
         53 . The method of  claim 40 , wherein said test device is a lateral flow test device. 
     
     
         54 . The method of  claim 40 , wherein said quantifying comprises quantifying a concentration of about 3 ng/mL to about 105 ng/mL of said one or more vitamin D molecules in said biological sample. 
     
     
         55 . The method of  claim 40 , further comprising detecting levels of said one or more vitamin D molecules in said biological sample by visualizing a signal appearing in said test device. 
     
     
         56 . The method of  claim 55 , wherein said quantifying comprises using an imaging device to provide an image of a detection membrane on said test device. 
     
     
         57 . The method of  claim 56 , wherein said quantifying further comprises using software on a programmed computer configured to quantify said one or more vitamin D molecules in said biological sample based on said image of said detection membrane. 
     
     
         58 . The method of  claim 40 , wherein said vitamin D binding agent is conjugated to a detection reagent. 
     
     
         59 . The method of  claim 58 , wherein said detection reagent is selected from the group consisting of: a gold particle, a latex particle, a carbon nanoparticle, a selenium nanoparticle, a silver nanoparticle, a quantum dot, a fluorescent compound, a dye, an enzyme, and a liposome.