Principle
The Etest is basically an agar diffusion method.
The Etest utilises a rectangular strip that has been impregnated with the drug to be studied. A lawn of bacteria is spread and grown on an agar plate, and the Etest strip is laid on top; the drug diffuses out into the agar, producing an exponential gradient of the drug to be tested. There is an exponential scale printed on the strip. After 24 hours of incubation, an elliptical zone of inhibition is produced and the point at which the ellipse meets the strip gives a reading for the minimum inhibitory concentration (MIC) of the drug.
Read more about this topic: Epsilometer Test
Famous quotes containing the word principle:
“The selfish spirit of commerce, which knows no country, and feels no passion or principle but that of gain.”
—Thomas Jefferson (1743–1826)
“Thus it seemed that this one hillside illustrated the principle of all the operations of Nature. The Maker of this earth but patented a leaf. What Champollion will decipher this hieroglyphic for us, that we may turn over a new leaf at last?”
—Henry David Thoreau (1817–1862)
“The principle of asceticism never was, nor ever can be, consistently pursued by any living creature. Let but one tenth part of the inhabitants of the earth pursue it consistently, and in a day’s time they will have turned it into a Hell.”
—Jeremy Bentham (1748–1832)