The Electo-Micro-Slide is a microscope slide of a new kid. This Printed Circuit Board, taking the exact dimension of a standard microscope slide, therefore fitting in a microscope slide holder present in most fluorescent microscope. The Electro-Micro-Slide receive electrical signals from the AC Dispatcher (ACD) and through 5 individual pins connected to physically segregated pairs of non connected gold electrodes. Connection between these electrode is done though depositing an agar pad across the pair of electrodes.

Holes between the each pair of electrodes allow for light to pass in both direction and for illumination through trans and fluorescent lighting of the studied sample. We used the Electro Planner to shock the program the experiment

The device is comprised of a 6 pin IDC connector for easy connection to the ADC through a flat ribbon cable, rendering manipulation in often crowded microscope chamber easy and tidy.

The device is largely inspired by the work showcased in [1]. However, as the device proposed by Stratford et. Al is manufactured through Vapor deposition, fabrication of their tool is impossible to many labs. Wit h the specific vision to enable these kind of experiments in labs beyond the fields of life science (such as in Robotics), we redesigned their device so that it could simply be ordered already manufactured and assembled, by the click of a button and for a very accessible price (less than 1$ per piece).

We orignally developed this device to invcestigte the possiblity of controling the expression of the pNasA promoter in B. subtilis though hyperpolarisation induced starvation of glutamine [2,3]. However, because of time constrain, we didn’t arrived to the point where we managed to assess the viability of this strategy.

We would like to point out nonetheless, that we have submited this idea to Muhernio Asally, author and director of the lab that produced the works affored mentioned, trhough a very graciously granted interview. His view on it is that it sounded feasible and, if we will get more opportunity in the future, we will attenpt this experiment.

We electroshocked bacteria stained with 10 uM Thioflavin T (a positively charged cationic dye reporting membrane potential) at frame 4.
Images were obtained though fluorescent microscopy (exposure for GFP Excitation and emission) on the Nikon XXXX at 60X Magnification

Cells were exposed to electrical signals generated by the MSH-2300q and controled by the Electro Planner. These signals were gated and dispatched by the to AC Dispatcher (ACD) the Electro-Micro-Slide
Cells were exposed to signals of varying amplitude (from 0.5 volts to 6 volts) at 100HZ and for 2.5seconds.

We can observe that the shock provoke a slight displacement of the entire field of view. The fluorescence intensity also change as expected though experiments conducted in [1]. However, because of the displacement, drawing conclusions from this experiments on the ability to change membrane potential is to be taken slightly

Overall, we showed that:

• observing bacteria's on the microscope with the Micro-Electro-Slide was achievable.
• Exposure of bacteria to electrical signals through conjoint used of the Micro-Electro-Slide, the ADC and the Electro-Planner have the desired effect