Compositions and methods for the detection of zinc

Abstract

The invention relates generally to compositions and methods for the detection of zinc. In particular, compositions and methods are provided to detect changes in cellular zinc concentration and to correlate them to cellular phenomena.

1 . A Zn-responsive probe comprising:
 a) a Zn-binding group configured to coordinate one or more Zn ions;   b) a signaling moiety configured to emit a detectable signal; and   c) an attachment group, wherein said attachment group is a chemically reactive with one or more functional groups.   
     
     
         2 . The Zn-responsive probe of  claim 1 , wherein the detectable signal of the signaling moiety is altered by coordination of one or more Zn ions by the Zn-binding moiety. 
     
     
         3 . The Zn-responsive probe of  claim 2 , wherein the signaling moiety comprises a fluorophore. 
     
     
         4 . The Zn-responsive probe of  claim 3 , wherein the fluorescence intensity, emission spectra, and/or excitation spectra of the signaling moiety is altered by coordination of one or more Zn ions by the Zn-binding moiety. 
     
     
         5 . The Zn-responsive probe of  claim 1 , wherein interaction of the attachment group with a chemically reactive functional group results in covalent or stable non-covalent attachment of the Zn-responsive probe to the functional group. 
     
     
         6 . The Zn-responsive probe of  claim 1 , wherein said Zn-binding group is attached to the signaling group, and the signaling group is attached to the attachment group. 
     
     
         7 . The Zn-responsive probe of  claim 6 , where one or more attachments are through a linker group. 
     
     
         8 . The Zn-responsive probe of  claim 5 , wherein the functional group is attached to a surface. 
     
     
         9 . A method of non-invasively detecting Zn release and/or uptake by a cell or cells comprising:
 a) contacting a sample comprising a cell or cells with a Zn-responsive probe;   b) detecting the signal emitted by the signaling moiety over time; and   c) correlating signal emitted with Zn concentration.   
     
     
         10 . The method of  claim 9 , wherein the sample comprises one or more oocytes. 
     
     
         11 . The method of  claim 9 , wherein the Zn-responsive probe is attached to a surface. 
     
     
         12 . The method of  claim 11 , wherein the surface is selected from the group comprising: a plate, bead, well, slide, biopolymer, cell surface, and tube. 
     
     
         13 . The method of  claim 9 , wherein said cell comprises a metaphase-II-arrested oocyte, wherein said method further comprises a step before step b) of contacting the sample with sperm, and wherein said detecting the signal comprises detecting a significant increase in extracellular Zn concentration based on a change in the signal of the Zn-responsive probe. 
     
     
         14 . The method of  claim 13 , wherein said correlating said signal comprises correlating the significant increase in extracellular Zn concentration to fertilization of the oocyte by the sperm. 
     
     
         15 . The method of  claim 14 , further comprising removing the oocyte from the Zn-responsive probe, and implanting the fertilized oocyte into a subject. 
     
     
         16 . The method of  claim 14 , wherein the Zn-responsive probe is attached to a surface. 
     
     
         17 . A method of evaluating the quality of an oocyte for fertilization comprising:
 a) contacting a surface with a sample comprising the oocyte, wherein said surface displays a plurality of Zn-responsive probes;   b) detecting the signal emitted by the Zn-responsive probes over time;   c) correlating the signal emitted with extracellular Zn concentration, wherein a decrease in extracellular Zn is indicative of an oocyte that is ready for fertilization.   
     
     
         18 . The method of  claim 17 , where the oocyte is in prophase-1-arrest upon contacting with the surface. 
     
     
         19 . The method of  claim 17 , wherein the Zn-responsive probe is attached to a surface. 
     
     
         20 . The method of  claim 19 , wherein the surface is selected from the group comprising: a plate, bead, well, slide, biopolymer, cell surface, and tube.