A programmable light delivery box for optogenetics experiments. This small and cheap light delivery system was used in several publications 1,2,3,4,5,6. Making something that flashes light isn't rocket science, but its important to have a robust, and hardy system for delivering light in a reliable and reproducible way while doing long and expensive optogenetics experiments. Additionally, not having tools for light delivery can be a major roadblock for those new to optogenetics.
Optogenetics? - Broadly, optogenetics is the process of delivering light to cells to control function, often using engineered genetic constructs. Light offers several advantages over using chemicals for controlling cell behavior including spatio-temporal control, being basically free and limitless, and having minimal biological side effects. With light you can induce gene expression, stop gene expression, degrade proteins, initiate protein-protein interactions, activate neurons, and much more.
What is it? - This light box delivers programmed doses of light and determined intervals. It has three independent outputs than can be programmed independently via a LCD screen. Useful assuming if you want to do some controls or comparisons, this feature is useful. You can program the timing, interval, intensity, etc. for each LED output.
- three independent programmable LED outputs
- program pulse length, interval, intensity
- powerful 700mA LEDs
- LCD screen
- swap out LED formats (4X3, 3X1 arrays, etc.)
- evenly target 12-well dishes for miscroscopy experiments (4x3)
- deliver light to yeast plates (3x1)
- swap out LED colors (blue, red, etc.)
Changing cell shape using light. Proteins involved with actin polymerization (SH3) were fused to a mutant plant protein that clusters in reponse to blue light. Constructs were transfected into monkey cells and ths Light Box was used to pulse blue light with the hypothesis that clustering SH3 domains would recruit other proteins involved with actin polymerization and disrupt the surrounding cytoskeleton. The figure below demonstrates this and shows that, as a result, we can also alter cell shape using light.
a) Strategy for clustering Nck SH3 domains. (b) Cells expressing CRY2olig–mCh–Nck and GFP–actin in dark, or 60 min post blue light (500 ms pulse, 488 nm, every 3 min). Scale bar, 20 μm. (c) Local photostimulation (within circle) of COS-7 cell expressing CRY2olig–mCh–Nck results in retraction of cell extension. Graph at right shows quantification of retraction (average and s.e.m., n=16) in cells expressing CRY2olig–mCh–Nck, or controls CRY2olig–mCh or mCherryN1 45 min post initial light exposure. ***P<0.001. NS, not significant. (d) Cells expressing CRY2olig–mCh–VCA, CRY2olig and GFP–actin in dark or 6 min post blue light (500 ms pulse, 488 nm, every 3 min). Inset images at right show detail within white square. Scale bar, 20 μm. (e) Stress fibres within cells expressing CRY2olig–GFP–VCA, CRY2olig and mCherry–actin are disrupted with light exposure.
If you'd like to build one yourself, create an issue on this repo (or star or watch it) so I can gauge interest and I can spend the time to put up instructions.
If you'd like to purchase one of these, please contact me. I've been commissed to build these for others before, so let me know if you'd like one. The overall cost for commissioning me to build one averages ~$500 (50% material, 50% labor), with the main material cost being the cost is the LEDs, which can be quite expensive. The design is robust and previous builds have all latest multiple years in the lab with no issues.
Demonstrating the input LCD screen. Its pretty straight forward. You can select the output (1, 2, or 3) and the light delivery characteristics (interval, pulse length, pulse intensity). The screen will also disply how long the program has been running for.
Up to three sets of LED arrays can be plugged into the front panel. Outputs are driven by a LED driver and support a variety of formats (4x3, 3x1, etc.).
Hole for plugging in the Arduino USB-C cable. Ventilation on the other side.
Nothing really interesting here...
Here are several papers that have used this design...
- Pathak, G. P. et al. Bidirectional approaches for optogenetic regulation of gene expression in mammalian cells using Arabidopsis cryptochrome 2. Nucleic Acids Res. 45, e167 (2017).
- Taslimi, A. et al. Optimized second-generation CRY2-CIB dimerizers and photoactivatable Cre recombinase. Nat. Chem. Biol. 12, 425–30 (2016).
- Taslimi, A., Vrana, J. D., et al. An optimized optogenetic clustering tool for probing protein interaction and function. Nature communications 5, 4925 (2014).
- Pathak, G. P., Strickland, D., Vrana, J. D. & Tucker, C. L. Benchmarking of optical dimerizer systems. ACS Synth Biol 3, 832–8 (2014).
- Hughes, R. M., Vrana, J. D., Song, J. & Tucker, C. L. Light-dependent, Dark-promoted Interaction between Arabidopsis Cryptochrome 1 and Phytochrome B Proteins. Journal of Biological Chemistry 287, 22165–22172 (2013).
- Tucker, C. L., Vrana, J. D. & Kennedy, M. J. in Current protocols in cell biology / editorial board, Juan S. Bonifacino ... [et al.] 64, 17.16.1–20 (Current protocols in cell biology / editorial board, Juan S. Bonifacino ... [et al.], 2014).