Methods of detection using X-ray fluorescence
The present invention relates, in part, to methods of using X-ray fluorescence (XRF) spectrometry for analyzing (e.g., measuring) the binding of a soluble target to an insoluble material.
1. A method for measuring binding of a soluble target to an insoluble material comprising:
exposing a solution comprising the soluble target to the insoluble material thereby allowing the formation of a complex comprising the soluble target and the insoluble material;
removing the solution comprising unbound soluble target and retaining the insoluble material;
resuspending the insoluble material in a second solution comprising at least one non-volatile component;
drying the insoluble material in a well plate; and
measuring the X-ray fluorescence (XRF) of the soluble target bound to the dried insoluble material within the well plate.
2. The method of claim 1 , wherein the soluble target comprises at least one chemical element with an atomic number greater than 9.
3. The method of claim 1 , wherein the soluble target is selected from an inorganic ion or inorganic compound, an organic ion or organic compound, and a biological molecule.
4. The method of claim 3 , wherein the soluble target is a metal ion.
5. The method of claim 1 , wherein the insoluble material comprises a particle.
6. The method of claim 5 , wherein the particle has an average diameter between about 1 μm and 500 μm.
7. The method of claim 1 , wherein the insoluble material is selected from a chelator, a biological molecule such as a peptide, modified peptide, peptoid, protein, nucleic acid, oligonucleotide, liposome, micelle, and proteoliposome.
8. The method of claim 1 , wherein the insoluble material is a cell.
9. The method of claim 1 , wherein the insoluble material comprises at least one chemical element with an atomic number greater than 9.
10. The method of claim 1 , wherein volume of insoluble material used is between about 0.1 μl and about 2 μL.
11. The method of claim 1 , wherein the removing is carried out by centrifugation, aspiration, decanting, pipetting, and/or filtrating.
12. The method of claim 1 , wherein the well plate is a 96, 384, or 1536 multiwell plate.
13. The method of claim 1 , wherein the well plate comprises a film or a surface that is largely transparent to X-rays.
14. The method of claim 1 , wherein multiple soluble targets are tested.
15. The method of claim 1 , wherein multiple concentrations of a single soluble target are tested.
16. The method of claim 1 , wherein multiple insoluble materials are tested.
17. The method of claim 1 , wherein multiple concentrations of a single insoluble material are tested.
18. The method of claim 1 , wherein solution further comprises a modulator that modulates the binding between the soluble target and the insoluble material.
19. The method of claim 18 , wherein multiple modulators are tested.
20. The method of claim 18 , wherein multiple concentrations of a single modulator are tested.
21. The method of claim 1 , wherein the method is utilized to measure the binding affinity of the soluble target and the insoluble material.
22. The method of claim 1 , wherein the method is utilized to characterize the binding between different combinations of soluble targets and insoluble materials.
23. The method of claim 1 , wherein the method is utilized to characterize the binding of a soluble metal ion to a chelator.
24. The method of claim 1 , wherein the method is utilized to characterize the binding of a soluble target to a cell.
25. The method of claim 8 , wherein the insoluble material is a non-adherent cell.
26. The method of claim 24 , wherein the method is utilized to characterize the binding of a soluble target to a non-adherent cell.