An open-hardware platform for optogenetics and photobiology

Abstract

In optogenetics, researchers use light and genetically encoded photoreceptors to control biological processes with unmatched precision. However, outside of neuroscience, the impact of optogenetics has been limited by a lack of user-friendly, flexible, accessible hardware. Here, we engineer the Light Plate Apparatus (LPA), a device that can deliver two independent 310 to 1550 nm light signals to each well of a 24-well plate with intensity control over three orders of magnitude and millisecond resolution. Signals are programmed using an intuitive web tool named Iris. All components can be purchased for under $400 and the device can be assembled and calibrated by a non-expert in one day. We use the LPA to precisely control gene expression from blue, green, and red light responsive optogenetic tools in bacteria, yeast, and mammalian cells and simplify the entrainment of cyanobacterial circadian rhythm. The LPA dramatically reduces the entry barrier to optogenetics and photobiology experiments.

Light-Inducible Recombinases for Bacterial Optogenetics

“…To perform these tests, we used a light plate apparatus (LPA). 31 We exposed samples to 465 nm blue light using LEDs for one hour and then took samples for polymerase chain reaction (PCR) immediately following light exposure. To verify that the recombinase was excising the target DNA properly, we first used PCR to check the length of the plasmid region containing the loxP-flanked terminator with and without exposure to light.…”

“…The next day, cultures were refreshed 1:100 in selective LB and induced for 2 hours with 100 μ M IPTG unless otherwise noted. Blue light exposure was performed using a LPA, 31 with two 465 nM wavelength LEDs per well (ThorLabs LED465E), outputting a total of 120 μ W/cm 2 . Unless otherwise noted, cultures were exposed to blue light for 1 hour.…”

A photoconversion model for full spectral programming and multiplexing of optogenetic systems

“…For each experiment, 192 cultures were grown in 500 ll volumes within 24-well plates (Arc-ticWhite AWLS-303008), sealed with adhesive foil (VWR 60941-126). Experiments were performed using eight 24-well LPA instruments (Gerhardt et al, 2016), enabling precise control of two LEDs to define the optical environment of 192 cultures at a time. LPA program files were generated using Iris (Gerhardt et al, 2016) and a custom Python tool (Dataset EV9).…”

Stimulus-responsive viral vectors for controlled delivery of therapeutics

“…For in vitro scenarios, the properties of the input light stimulus (e.g. wavelength, duration, intensity) can be controlled easily using the recently developed Light Plate Apparatus (LPA) [95]. The 24-well format of the LPA allows for testing of multiple light conditions simultaneously in order to more quickly identify optimal parameters leading to desired gene expression profiles.…”