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Team:TU Munich/lab/notebook/solidmatrix
From 2011.igem.org
Preliminary Experiment 1: The Search For The Perfect Solid Medium (most work done by Thorsten, Anna, Simon)
04-11-2011
light transmission of solid agar, different agar concentrations and growth media
Purpose:
In order to create the 3D-Printer based on a double-light-sensitive-promotor, it is not only necessary to immobilize the cells within a solid medium but also to be able to induce the protein expression at a definied spot. Thus, we want to examine the light transmission properties of different solid media.
Procedure:
To gain data on the light transmission of different solid media, different compositions of media were produced and poured into 1 ml cuvettes while they were still liquid. After gelation, a transmission spectrum (230 nm - 750 nm) was recorded for each sample
Agar with LB-Medium:
| Agar-concentration [w/v] | Agar-Agar [g] | LB-Medium [ml] | number of cuvettes |
| 0.5 % | 0.05 | 10 | 3 |
| 1.0 % | 0.10 | 10 | 3 |
| 1.5 % | 0.15 | 10 | 3 |
| 2.0 % | 0.20 | 10 | 3 |
| 2.5 % | 0.25 | 10 | 3 |
| 3.0 % | 0.30 | 10 | 3 |
Agar with M9-Medium:
| Agar-concentration [w/v] | Agar-Agar [g] | M9-Medium 5x [ml] | distilled water [ml] | number of cuvettes |
| 0.5 % | 0.05 | 2 | 8 | 4 |
| 1.0 % | 0.10 | 2 | 8 | 3 |
| 1.5 % | 0.15 | 2 | 8 | 3 |
| 2.0 % | 0.20 | 2 | 8 | 3 |
| 2.5 % | 0.25 | 2 | 8 | 3 |
| 3.0 % | 0.30 | 2 | 8 | 3 |
Agarose with M9-Medium:
| Agarose-concentration [w/v] | Agarose [g] | M9-Medium 5x [ml] | distilled water [ml] | number of cuvettes |
| 0.5 % | 0.05 | 2 | 8 | 4 |
| 3.0 % | 0.30 | 2 | 8 | 3 |
Results & Discussion:
The transmission spectra were saved locally on the lab-computer (upload?)
LB-medium has low tranmission values at shorter wavelengths (hence its yellow appearance) and should therefore be avoided in our experiment if possible. If a clear medium (such as M9) is sufficient for our purposes it should be chosen. It has no significant absorbtion of blue light, which makes the application of a promotor sensitive to blue light feasible.
Gels prepared with Agarose were clearer than those prepared with Agar-Agar.
The transmission values are higher at lower concentrations of the gelling agent.
Is a glas or plastic container neccessary for solid media?
Purpose:
We figured that if we could do without a glas or plastic container surrounding the solid medium, this would increase the precision of our light-beam aiming at the cells that are to be induced (no light refraction at the container walls, etc.).
Procedure:
To examine if it is possible to make a detachted, self-supporting block of agar, we made a 40 ml block of 0.5 % (w/v) Agar with M9-Medium in a small beaker glass. After the gellation process we turned it out and left it to stand over night.
Results & Discussion:
The block had lost a lot of water over night, so that it was standing in a puddle. Therefore it's not possible to make a detachted, self-supporting block of agar (0.5 % w/v).
