Composition
It usually consists of polysaccharides, but can be composed of other materials (e.g., polypeptide in B. anthracis). Because most capsules are water soluble, they are difficult to stain using standard stains because most stains do not adhere to the capsule. For examination under the microscope, the bacteria and their background are stained darker than the capsule, which doesn't stain. When viewed, bacterial cells as well as the surface they are on, are stained dark, while the capsule remains pale or colorless and appears as a ring around the cell.
Read more about this topic: Bacterial Capsule
Famous quotes containing the word composition:
“Give a scientist a problem and he will probably provide a solution; historians and sociologists, by contrast, can offer only opinions. Ask a dozen chemists the composition of an organic compound such as methane, and within a short time all twelve will have come up with the same solution of CH4. Ask, however, a dozen economists or sociologists to provide policies to reduce unemployment or the level of crime and twelve widely differing opinions are likely to be offered.”
—Derek Gjertsen, British scientist, author. Science and Philosophy: Past and Present, ch. 3, Penguin (1989)
“The naive notion that a mother naturally acquires the complex skills of childrearing simply because she has given birth now seems as absurd to me as enrolling in a nine-month class in composition and imagining that at the end of the course you are now prepared to begin writing War and Peace.”
—Mary Kay Blakely (20th century)
“It is my PRIDE, my damn’d, native, unconquerable Pride, that plunges me into Distraction. You must know that 19-20th of my Composition is Pride. I must either live a Slave, a Servant; to have no Will of my own, no Sentiments of my own which I may freely declare as such;Mor DIE—perplexing alternative!”
—Thomas Chatterton (1752–1770)