Gases

Production of gases can be monitored in several ways. A method used in clinical labs employs a fluorescent molecule to detect bacteria growing in blood taken from patients who are suspected of having a bloodstream infection. The slight

(a)

Figure 4.16 Measuring Turbidity with a Spectrophotometer (a)The cloudiness, or turbidity, of the liquid in the tube on the left is proportional to the concentration of cells. (b)The percentage of light that reaches the detector is inversely proportional to the optical density.To use turbidity to estimate cell number, a one-time experiment must be done to determine the correlation between cell concentration and optical density of a culture.

Figure 4.16 Measuring Turbidity with a Spectrophotometer (a)The cloudiness, or turbidity, of the liquid in the tube on the left is proportional to the concentration of cells. (b)The percentage of light that reaches the detector is inversely proportional to the optical density.To use turbidity to estimate cell number, a one-time experiment must be done to determine the correlation between cell concentration and optical density of a culture.

4.7 Bacterial Growth in Laboratory Conditions 101

decrease in pH that accompanies the production of CO2 increases the fluorescence. A method routinely used in the laboratory is to include an inverted small tube, called a Durham tube, in a broth of sugar-containing media. If bacteria produce gas as a result of degradation of the sugar, bubbles will be trapped in the tube.

Was this article helpful?

0 0
You Are What You Eat

You Are What You Eat

Nutrition is a matter that people spend their careers learning about and requires volumes of books to explain. My objective is to instruct you how to consume a healthy nutritional diet that aids your body in burning off fat instead of storing it. You do not require overwhelming science to get this.

Get My Free Ebook


Post a comment