Microbe Mission B/C

[Koolman]

Is there an easy way to identify spirochetes as compared to spirilla?

[RyanMist]

Spirilla have less twists that are more apart while spirochetes have more twists closer together... like a corkscrew.

[jimmy-bond]

Is there an easy way to identify spirochetes as compared to spirilla?

Adding on to what RyanMist said, spirochetes usually appear longer than spirilla. Also, spirochetes have axial filaments as opposed to spirilla, which have polar flagella.

[RyanMist]

What is the best way to differentiate from confocal and fluorescent microscopes?

[Alex-RCHS]

What is the best way to differentiate from confocal and fluorescent microscopes?

Confocal is a specific type of fluorescent microscope. It uses pinholes to ensure that it only receives light from a very small point on the imaged object at a time. That light signal is interpreted by a computer as data, and the microscope scans the entire object, one point at a time, recording the intensity of the light at that point. It then pieces together all of that data into a 3D image of the object.

The other main type of fluorescent microscopy is wide-field fluorescent microscopy, where an object stained to fluoresce is imaged in full.

Similarities: Each one uses fluorophores -- molecules that fluoresce, or release light immediately after being hit by a photon -- to image the sample. In both cases the images usually appear as bright colors on a dark background.

Differences: Confocal microscopy generates a 3D image, whereas wide-field fluorescent microscopy generates a 2D image. Confocal microscopy often has a higher resolution as well. Confocal microscopy uses a computer to assemble the images, but with wide-field fluorescent microscopy you can look directly through the objectives at the image (usually).

[RyanMist]

Thanks. Need to add that to cheat sheet

[fabishkf]

On the Wisconsin state exam, there was a calculation problem where you had to calculate the concentration of bacteria in the original flask given the serial dilutions done to it and how many bacteria there were on certain plates (after some dilutions were plated). I had read before that to calculate this you multiply the dilution factor by the number of bacteria on that plate (if between 30 and 300). However, the test gave two plates with values between 30 and 300 (one with 31 and one with 208 or something like that). In the future, which plate should I use? I am wondering this because when multiplied out they gave different concentrations. I might have done it wrong also, and if so can you correct my reasoning? Thanks.

[RyanMist]

On the Wisconsin state exam, there was a calculation problem where you had to calculate the concentration of bacteria in the original flask given the serial dilutions done to it and how many bacteria there were on certain plates (after some dilutions were plated). I had read before that to calculate this you multiply the dilution factor by the number of bacteria on that plate (if between 30 and 300). However, the test gave two plates with values between 30 and 300 (one with 31 and one with 208 or something like that). In the future, which plate should I use? I am wondering this because when multiplied out they gave different concentrations. I might have done it wrong also, and if so can you correct my reasoning? Thanks.

From what I understand you should use the one with 208. It is more in the middle of 30 and 300. But I think either one would be fine.

[Tailsfan101]

The rules speaks of special Nationals topics:

...xii. Causes and effects of microbial population explosions
xiii. Microbial competition and communication
xiv. Microbiomes
xv. Biofilms

Does anyone have any knowledge about these topics, or websites I could look to for information?

[whythelongface]

The rules speaks of special Nationals topics:

...xii. Causes and effects of microbial population explosions
xiii. Microbial competition and communication
xiv. Microbiomes
xv. Biofilms

Does anyone have any knowledge about these topics, or websites I could look to for information?

Wikipedia? :Thinking:

Literally just Google "biofilm", "Microbiome", and "quorum sensing".