General Microbiology Lab Briefing

This week we’re doing Exercise 2:  The Kingdom Protista

• Be sure to read the introductory portion of the lab book for this lab before you come to lab.  It is also a good idea to review the lecture information that we have gone over.  [NOTE that the Protista lecture (with pictures) is posted in the lecture portion of Vancko Hall.]
• The Protista consists of two subkingdoms:  Algae and Protozoa
• Be sure to draw and label your drawings.  Also include a brief description of what you see.

Here is what you’ll be looking at of the Protozoa

• Live Cultures of the following — all can be easily viewed at 100x and 400x (draw them at either magnification):
  • Paramecium — these are kind of speedy you may want to slow them down with some Protoslo solution — a drop of it on your slide then some of the culture.
  • Amoeba — your instructor may need to fish these out for you — they are a bit hard to capture with a pipet because they are kind of sparse in the culture.
  • Vorticella – a stalked ciliated protozoan that looks like a wine goblet!  The cilia create a vortex or mini-whorlpool that draws the bacteria in the water toward the gullet.
  • NOTE:  be sure to view the live protozoans in your first lab — they probably will not live to Wednesday or Thursday!
• Prepared slides of
  • Trichomonas vaginalis — causes an STD.  These are small and are stained pink or lavender. [400x]
  • Trypanosoma – are hemoparasites causing sleeping sickness.  So this is a blood slide — best viewed at 1,000x.  The parasites look kind of like worms between the red blood cells. Why are they wavy on one side? What is that called?
    • Be sure to listen to the podcast on Trypanosoma available in Vancko Hall lecture section.
  • Paramecium – 100x or 400x.
  • Amoeba – 100x or 400x — the colors are due to stains that have been used in the preparation of the slides.
  • For all of these make a note about what group of Protozoa they belong to — Mastigophora, Sarcodina, Ciliata, or Apicomplexa!

Algae:

• Live cultures of (mostly can be viewed at 100x but for some you may need 400x):
  • Closterium – a green alga that looks like a green cigar or new moon (some will have a curve to them).
  • Spirogyra - a filamenouts green alga with a spiral-shaped chloroplast.
  • Variety of live algae from various habitats.  I’ll let you know where from after I collect them!
• Prepared slides of (100x and 400x):
  • Volvox
  • Various diatoms — these are slides I prepared for my master’s degree work on a small stream.  I’ll include my thesis so you can look at the pictures of these as well.
    • What you are looking for are regular shapes — round or lancet shaped usually.  These have been “cleaned” so all you are seeing is their silica cell walls.

Cyanobacteria:

• I include the Cyanobacteria here because they are metabolically similar to the algae because they generate oxygen during the light reactions of photosynthesis.  In addition they are found in aquatic habitats like the algae.  They also tend to be green(ish) — actually they are sometimes called “Bluegreen Algae”.  They contain chlorophyll a and a red pigment (phycoerythrin) and a blue pigment (phycocyanin).  Note that they do not have any internal structure (no chloroplasts).  For this reason they are classified with the bacteria.
• Live cultures of
  • Oscillatoria (400x)
  • There may be some Cyanobacteria in the mixed cultures from streams or ponds.
• Prepared slides of
  • Oscillatoria (400x)

  For more information on Cyanobacteria see this website:  http://www.ucmp.berkeley.edu/bacteria/cyanolh.html