Instruments, modules, and methods for improved detection of edited sequences in live cells
The present disclosure provides instruments, modules and methods for improved detection of edited cells following nucleic acid-guided nuclease genome editing. The disclosure provides improved automated instruments that perform methods—including high throughput methods—for screening cells that have been subjected to editing and identifying cells that have been properly edited.
1. A method for enriching edited cells during CRISPR editing comprising:
transforming cells with one or more vectors comprising an inducible promoter driving transcription of a coding sequence for a CRISPR nuclease, and an inducible promoter driving transcription of a guide nucleic acid sequence and a DNA donor sequence;
diluting the transformed cells to a cell concentration to substantially singulate the transformed cells on a substrate;
growing the cells on the substrate for 2-200 doublings;
initiating editing by inducing the inducible promoters driving transcription of the guide nucleic acid and CRISPR nuclease;
growing the induced cells into colonies; and
selecting or pooling slow-growing colonies on the substrate, wherein cells from the slow-growing colonies are enriched for edited cells.
2. The method of claim 1 , wherein the inducible promoter driving expression of each of the guide nucleic acid and the CRISPR nuclease is a same inducible promoter.
3. The method of claim 2 , wherein the inducible promoter is a pL promoter.
4. The method of claim 1 , wherein all of the coding sequence for the CRISPR nuclease, guide nucleic acid sequence and DNA donor sequence are on the same vector.
5. The method of claim 1 , wherein the coding sequence for the CRISPR nuclease is on a first vector and the guide nucleic acid sequence and DNA donor sequence are on a second vector.
6. The method of claim 1 , wherein the DNA donor sequence further comprises a PAM-altering sequence.
7. The method of claim 1 , wherein the one or more vectors each further comprise a gene for a selectable marker.
8. The method of claim 7 , further comprising adding selective agents to the substrate to select for the selectable marker(s) on the one or more vectors.
9. The method of claim 7 , wherein there are two vectors and each vector has a different gene for a selectable marker.
10. The method of claim 1 , wherein the engine vector further comprises a recombineering system.
11. The method of claim 1 , wherein the substrate is selected from an agar plate and a device with solid walls.
12. A method for enriching edited cells during CRISPR nuclease editing comprising:
transforming cells with one or more vectors comprising a promoter driving transcription of a coding sequence for a CRISPR nuclease, and an inducible promoter driving transcription of a guide nucleic acid sequence and a DNA donor sequence;
diluting the transformed cells to a cell concentration to substantially singulate the transformed cells on a substrate;
growing the cells on the substrate for between 2 and 200 doublings;
initiating editing by inducing the inducible promoter; and
growing the cells to form colonies of terminal size.
13. The method of claim 12 , wherein the promoter driving transcription of the guide nucleic acid is a pL promoter.
14. The method of claim 12 , wherein the promoter driving expression of the CRISPR nuclease is an inducible promoter.
15. The method of claim 14 , wherein the inducible promoter driving transcription of each of the guide nucleic acid and the coding sequence for the CRISPR nuclease is the same inducible promoter.
16. The method of claim 15 , wherein the inducible promoter driving transcription of the coding sequence for the CRISPR nuclease and driving transcription of the guide nucleic acid is a pL promoter.
17. The method of claim 12 , wherein the DNA donor sequence further comprises a PAM-altering sequence.
18. The method of claim 12 , further comprising adding selective agents to the first substrate to select for the one or more vectors.
19. The method of claim 12 , wherein the CRISPR nuclease is a MADzyme nuclease.
20. The method of claim 12 , further comprising pooling the terminal-size colonies.