I want to measure photaxicity properties of a Cyanobacteria. Some scientists have used 0.5% agar in BG-11 media and unidirectional light to measure the ability of Cyanobacteria to move toward light. How should I set up the unidirectional light system for that experiment?
I made some successful trials some time ago. In my case I used 1.5% Agar in BG11. I'm unsure what you mean by set up, just inoculate your strain in one half of the plate and let it grow under usual light conditions (non-directional). One you have observable amount of biomass, mark the initial position of the biomass and place the plate next to a lateral source of light. Hope it helps, good luck!
Use a glass pipette or a Pasteur pipette filled with your media. Inoculate it with your culture in one side and only illuminate the other side...covering all the pipette with a black cover..only the side without inoculation should be exposed to light .
People I know that look at phototaxis just use droplets of culture on BG11-Agar plates.
The percentage of the agar is not that important. We use between 0.75% and 0.9%.
Just drop a dense culture onto the plate and let it stand under the sterile hood for the drop to sink into the agar.
For unidirectional light you can just use a closed box with a "window" cut out at about the height you want to put your plate. Put a lamp in front of that window.
Good luck.
Photo means light, and taxis means responsive-movement. So, a range of agar concentrations will work for the same. Here the important criteria is the direction of favourable light, which can differently be set-up. For examples, from top of a petriplate, from bottom of a petriplate or from one side (while cyanobacteria is inoculated on the other end opposite to light source). This task is easy as small fluorescent bulbs/tubes can be used in a table lamp set-up on a shelf where no other source of light is available. If this experiment need to be done in a dedicated culture room, then phototaxis experimental set-up can be isolated from rest by suitable use of black cloths. For, unicellular cyanobacteria low agar concentration is suggested, while filamentous cyanobacteria will work at 0.5-2% agar concentration.
- Badges
- Science method