The story of a butterfly that explains how species evolve.

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People often wonder or rather doubt how new species are formed. Some people doubt the whole phenomenon of evolution because it's "a theory of evolution". However, in reality, evolution happens and we can find evidence of it in nature. Here, for instance, a species of butterfly in Amazon region was found to have evolved from the hybridization of two other species of butterflies. Interestingly, the descendants of all these three lineages of butterflies coexist in same geographical region and two of these occasionally mate with each other.
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Laminar Flow Hood

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If you are culturing any microorganism in lab, e.g., E. coli, algae, animal cell, plant tissue; you need to have a laminar flow hood. Previously and even now in many labs, bacteria are cultured by working between two burners. The whole idea is to keep a sterile environment so that nothing except your organism of interest goes into you culture medium.

Laminar Hood maintains a positive pressure cabin inside so that bacteria from outside don't enter the hood. It takes in air filters using a hepa-filter for bacteria and pumps the air outside from where you are working.



Laminar hood must have following features:
  1. A UV light source to sterilize the hood.
  2. A door that can be opened/closed while working. This insures safety while the UV light is on.
  3. A white light source for illumination the  hood while you work.
  4. Air flow which could be switched on and off.
 Using the hood:
  1. Close the door of the hood.
  2. Switch on UV for 15 to 20 min.
  3. Switch on air flow.
  4. Switch off the UV light.
  5. Switch on white light.
  6. Open the hood door.
  7. Wipe the working surface with 70% ethanol.
  8. Do your work.
  9. Close the hood door.
  10. Switch on the UV light.
  11. Switch off the air flow and white light.
  12. Keep the UV light on for 15-20 min.
  13. Switch off the UV light.
Additional Information:
   People use burners in the hood. You should NOT use burner inside the hood. The flame of the burner actually causes turbulence in the air flow which might result in contamination. Also if the hepa filter is situated on the roof of the hood, it may get damaged.
Always keep the hood clean.

Have a happy culture.

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