Archive for the ‘Microbiology’ Category
Using A Micropipette: Youtube demonstration
| Demonstration for using a Micropipette. Must watch! |
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Chemotaxis- Bacterial Movement!
Still don’t have any faster way to get online (again posting from Nokia N72 using Vodafone GPRS!) but I’m expecting to get a broadband connection installed at my home by this Monday.
And I discovered the answer to that question in that book itself. Here’s the solution-
For distinguishing a Procaryote from Eucaryote without using a Microscope, the phenomena of “Chemotaxis” may be considered.
Bacteria, falls under Procaryotes shows movement towards certain chemicals known as “Attractants” also they show movement away from some chemicals, named as “Repellents”.
This type of behavior is shown by bacteria only.
Demonstration:-
1:-Take a capillary tube, fill it with some proper attractant & place it over a bacterial suspension. On diffusion of attractant from the end of the capillary, bacteria will swim up that capillary tube.
Number of bacteria in that capillary tube will determine the strength of attractant & rate of chemotaxis.
2:- If bacteria are placed in the centre of a petri dish of a semisolid agar containing an attractant, the bacteria will exhaust the local supply & then swim outward following the attractant gradient they have created. Result is expanding ring of bacteria.
And when a disk of repellent is placed in a petri dish of semisolid agar & bacteria, the bacteria will swim away from repellent, creating a clear zone around the disk.
Posting it from my Nokia N72
Don’t have any better way to get online this time
so I thought of trying Opera browser for Symbian phone (courtesy Apoorv).
My high school friend Apoorv is with me and he’s going to stay here for two days.
One thing that bugging me a lot since I started studying Procaryotic cell structure is a “Critical Thinking Question” from my book “Prescott, Harley & Klein’s Microbiology”.
Here’s that question-
If you could not use a microscope, how would you determine whether a cell is Procaryotic or Eucaryotic? Assume the organism can be cultured easily in the laboratory.
“typing in text field using Opera’s T9 dictionary is a suck!”


