Microbiology

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I am currently planning a project involving the effect of a colloidal silver solution on bacterial biofilms. I have the following general procedure, although I am unsure which the following things
-Whether or not it is the correct way of growing biofilms and overnight culture.
-Whether it is a smart idea to grow the bacteria within the cuvette. (I am doing this because it is the only type of container that can fit within the spectrophotometer).
-How I should go about using the spectrophotometer.
-How to prepare the crystal violet and colloidal silver solution.
Any changes or suggestions would be greatly appreciated.

Streaking Technique:
https://d1ca4yhhe0xc0x.cloudfront.net/F ... es_img.jpg
Overnight Culture Preparation:
1. Pipette 6 mL of fresh LB medium into the test tube.
2. Place inoculation loop onto the agar plate with the bacterium in order to obtain colonies.
3. Insert loop into the liquid medium and stir all throughout to ensure a homogenous solution.
4. Incubate at 37 degrees overnight.
Biofilm Formation:
1. Label cuvettes E Coli: #1: 40 uL, #2: 60 uL, #3: 80 uL; Pseudomonas putida: #1: 40 uL, #2: 60 uL, #3: 80 uL;
2. Pour 2 mL of LB medium into the cuvette, and pour the appropriate amount of the colloidal silver solution. After this, pour 40 uL of an overnight culture.
3. As a control, 20 µL of ethanol: water (1:1) was used instead of the solution.
4. The cuvettes were incubated at 37°C.
5. Shake out the liquid.
6. Next, add 1.5 mL of crystal violet solution to each cuvette. Wash them with water three times and let dry.

The main rationale behind using the crystal violet is that the more intense the crystal violet, the more biofilm that is present. I am unsure whether or not my procedure is correct or if the values I am using are correct. I based this project on a similar one found in the Topic Selection Wizard: https://www.sciencebuddies.org/science- ... i-bacteria

These are my main materials:
Colloidal silver solution: https://www.amazon.com/Natural-Path-Sil ... B000BT4CFE
E coli: https://www.carolina.com/bacteriophage- ... ion=e+coli
Crystal violet solution: https://www.carolina.com/specialty-chem ... tal+violet
Spectrophotometer: https://www.vernier.com/training/videos ... oplay=true