Light can kill cultured cells. This can be addressed by removing components of cell culture media that are converted into free radicals by light.

1. Surpassing the cytotoxic
limits of light
DR. JOHN H. STOCKLEY

2. Overview
1. Light in Biology
2. All CNS cells are altered by light
3. The source of damage is in the media and in the cells
4. Using MEMO prevents generation of toxic products in media
5. Using MEMO and SOS prevents generation of toxic products inside cells
6. NEUMO and SOS rescue neurons and astrocytes from photo-damage

3. Light tools
1. Optogenetics
• ChR2, CRY2, OPN4, LOV
2. Live cell imaging
• Super-resolution, voltage imaging, ion imaging, etc….
3. Light triggered drug delivery
• Caged DNA, drugs or proteins for controlled release with light
4. Fluorescent activated cell sorting (FACs)

4. Light kills cells
Microscope

5. Neuronal death in normal media
1 mw/ mm2 continuous for 1 second = 1 kJ/m2

6. Astrocytes retract processes in normal media

7. OPCs die in normal media
OPC
Oligodendrocyte
Demyelinatio
n

8. Using OPC vulnerability to solve photo-damage

9. Using OPC vulnerability to solve photo-damage

10. Using OPC vulnerability to solve photo-damage
+

11. Two sources of photo-toxicity
Media
generated
toxicity
Cell
generated
toxicity

12. Neuronal and Astrocyte protection
+

13. Improvement in Calcium Imaging

14. MEMO does not alter OPC functionality

15. Acknowledgements
1. Ragnhildur Káradóttir, University of Cambridge
Kimberley Evans, Moritz Matthey, Katrin Volbracht & Sylvia Agathou
2. Juan Burrone and Jana Mukanowa, Kings College London
3. Rachel Atfield and Laura Donnelly of Cambridge Enterprise