Metal-based covalent viability reagent for single cell analysis
The present invention provides a robust viability stain for methods utilizing elemental analysis. A population of cells is contacted with an effective dose of a non-chelated biomacromolecule-reactive metal derivative, which selectively crosses the plasma membrane of non-viable cells, and which covalently modifies a biological macromolecule within the cell, for a period of time sufficient to permit entry into non-viable cells. The population of cells is then washed free of unbound viability reagent; and the presence of the metal within the cells is detected, wherein non-viable cells are selectively labeled with the viability reagent.
1. A method of distinguishing a viable cell from a dead cell, the method comprising;
(a) contacting the cell with a viability agent that is a compound that contains platinum where the platinum is non-chelated and the viability agent is in a concentration effective to react with biomacromolecules in a non-viable cell;
(b) incubating the resultant contacted cell from step (a) for a period of time sufficient to permit entry of the viability reagent into a non-viable cell;
(c) washing the resultant incubated cell from step (b) free of unbound viability reagent; and
(d) performing elemental mass spectrometry-based detection to determine if platinum is present in the resultant washed cell from step (c), wherein a non-viable cell is selectively labeled with platinum relative to a viable cell.
2. The method of claim 1 , wherein the cell is in a heterogeneous population of cells.
3. The method of claim 1 , wherein the platinum content of the viability reagent is a mixture of isotopes.
4. The method of claim 1 , wherein the platinum content of the viability reagent is synthetically enriched for an isotope.
5. The method of claim 1 , wherein the viability reagent covalently reacts with protein in the cell.
6. The method of claim 1 , further comprising analyzing of the cell for additional analytes by elemental or fluorescent detection.
7. The method of claim 1 , wherein the cell is fixed and permeabilized following contacting with the viability reagent.
8. A method of distinguishing a viable cell from a dead cell, the method comprising:
(a) contacting the cell with cisplatin at a concentration effective to react with biomacromolecules in a non-viable cell;
(b) incubating the resultant contacted cell from step (a) for a period of time sufficient to permit entry of the cisplatin into a non-viable cell;
(c) washing the resultant incubated cell from step (b) free of unbound cisplatin; and
(d) performing elemental mass spectrometry-based detection to determine if platinum is present in the resultant washed cell from step (c), wherein a non-viable cell is selectively labeled with platinum relative to a viable cell.
9. The method of claim 8 , wherein the cisplatin is present at a concentration of from about 1 μM to about 250 μM.
10. The method of claim 8 , wherein the cisplatin is present at a concentration of from about 10 μM to about 50 μM.
11. The method of claim 8 , wherein the incubating step is from about 1 to about 30 minutes.
12. The method of claim 8 , wherein the incubating step is from about 1 to about 10 minutes.
13. The method of claim 8 , wherein the detection is performed by inductively coupled plasma mass spectrometry, secondary ion mass spectrometry; thermal ionization mass spectrometry, or atomic absorption mass spectrometry.
14. The method of claim 8 , wherein the detection is performed by mass cytometry.