By: Janet Grischy
Prions are infectious proteins thought to cause disease as viruses do, though they lack the DNA or RNA that forms the command structure of a virus. Prions have been implicated in scrapie, kuru, Creutzfeldt-Jakob disease, and in Bovine Spongiform Encephalopathy (BSE), also known as Mad...
By: Janet Grischy
Bacteria are prokaryotes, one of the three great classes of life. Their cells have no nuclei, and generally lack organelles, small sub-units bound in membranes. They are about a tenth the size of the eukaryotic cells found in plants and animals, on average, though a...
The role of algae in the ecological lifecycle
By: Jess Howe
Algae, whether red or green, have an important role in the ecosystem of this world. They start out in our oceans, are as food sources to the smallest of creatures who then get eaten by larger and larger creatures exponentially, till their influence gets to...
Differential staining of bacteria using known controls
By: Tami Port MS
There are many staining techniques that can be used to view bacteria. Simple stains employ only one dye, and provide information limited to cell shape and grouping. The use of differential stains is more complex. Differential protocols employ a series of dyes to distinguish different...
Tests for identification of bacteria: Differential staining, specialized media and API-20E
By: Tami Port MS
Gram, Acid Fast and Endospore stains; MacConkey's, Mannitol Salt, and Blood Agar media as well as the API-20 test strip all provide information to identify microbes. Most of these are procedures taught in introductory microbiology courses, and are useful in sorting bacteria into broad categories...
The role of bacteria in making cheese
By: Jess Howe
Bacteria's role in cheese making is important. Those little creatures that sometimes give us infections are also friendly at other times, we know - just how friendly is about to be shown, as I talk about two of my favorite things in the world:...
Blood agar (BPA) differential bacterial growth medium
By: Tami Port MS
Blood Agar is a bacterial growth medium that can distinguish normal from pathogenic bacteria based on the effect of bacterial hemolytic enzymes on red blood cells. * What Is a Growth Medium? * A growth medium (plural: media) is a mixture of nutrients, moisture and...
Microscopic viewing of bacteria under oil immersion
By: Tami Port MS
Before bacteria can be viewed through a microscope, a bacterial smear must first be created and then heat fixed. Heat fixing kills the microbes and firmly attaches them to the slide, so that the sample is not washed away during the staining procedure. * Simple...
MacConkey's agar (MAC) bacterial growth medium
By: Tami Port MS
When bacterial cultures are grown in a laboratory, they are growing in a captive environment, somewhat like a tiny microbial zoo. These captive-bred bacteria are totally dependent on people to provide the proper environment for their survival and growth. A nutrient-rich media is required in...
By: Tami Port MS
In order to view individual bacteria through a light microscope, a bacterial smear must be attached to a slide and then stained. Here is the procedure. First, use a wax pencil to draw a circle on the microscope slide to separate each type of bacteria...

 

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