“In the laboratory, a sterile inoculating loop is moved across the agar surface in a culture dish, thinning a sample and isolating individuals.” This statement describes which of the following?
a. Broth culture
b. Pour plate
c. Streak plate
d. Dilution plate

Question

“In the laboratory, a sterile inoculating loop is moved across the agar surface in a culture dish, thinning a sample and isolating individuals.” This statement describes which of the following?

a. Broth culture

b. Pour plate

c. Streak plate

d. Dilution plate

Accepted Answer

Hi, everybody. And welcome back. Our next problem says the Streak plate method is a laboratory technique that is primarily used to a create a diverse spectral culture B test the efficiency of a treatment C produce a pure culture or D test the nutrients present in the agri. Well, the key in arriving at the correct answer here is this phrase primarily used. And this one can be a little tricky and a multiple choice question because it means we might have more than one correct answer in the sense that it will answer the question truthfully or correctly. But we're looking for primarily meaning there'll be one answer, that's a better answer than the others. So that can be a little bit tricky because we can be misled. So this is actually an example of this. So when we think about street plates, it involves starting with a bacterial sample that is usually mixed species of bacteria. So this would be a sample taken from uh you know, an infected site, uh a urine sample or a sample of some puss or something like that. So the area that you want to look at that has bacteria, but is probably a mix. Since most locations in nature will have multiple species dwelling together, the sample is diluted greatly. So you dilute it dilute, it dilute it and then streaked on an agri plate. Thus, the streak plate method, and then if it's diluted sufficiently, you've spread out those mixed bacteria into individual cells on the plate, bacteria grow very rapidly multiply, very rapidly. So the individual bacterial cells will multiply until a visible colony is observed. So of course, once we see that colony on the plate, we know that all the cells in that colony are identical to the individual individual bac the individual bacterial cell they grew from. So you've now taken this mixed sample of different bacteria and the colonies on your plate are now different species of bacteria or different individuals. So you've separated out anything that was in your individual sample. So as you can see, this technique will choice c produce a pure culture. Now, why did I talk about this primarily used and warning you about other correct answers? Well, look at choice B test the efficiency of a treatment. You can use a street plate method to find to look for which antibiotic, for instance, would be best to treat a given uh infection. So I have a urine sample from someone with a urinary tract infection. I you know, dilute it, spread it on a plate and then try different antibiotics on the cultures that grow. And I would look to see which of those antibiotics actually kill what's in the sample. So I look for clear areas on my plate. So this would be an example of using the street plate method to test the efficiency of a treatment. So a correct description of a use of the street plate method, but our question says primarily used. So this is just one use and not the primary reason you do this which is to separate out individual species of bacteria from a mixed sample. So you can see we're on a test. This is choice B. Our answer is choice C you might hit on this. Think about that antibiotic sensitivity training or testing, excuse me and grab this as your answer without going further. So that's why you need to be real careful with things like primarily used, mostly used or most important things like that. And multiple choice questions, choice A create a diverse spectral culture. Well, that's the opposite of what we want to do. We've started with a diverse culture. We're trying to isolate the separate bacteria and then choice D test the nutrients present in the ager. This is another one that could be a method you might be wanting to look at. Um would these nutrients in this particular ager plate be sufficient to grow a kind of bacteria? But that wouldn't be the primary use. That would be a specific application you might use it for. So cross that off. So once again, the streak plate method is a laboratory technique primarily used to choice c produce a pure culture. See you in the next video.

“In the laboratory, a sterile inoculating loop is moved across the agar surface in a culture dish, thinning a sample and isolating individuals.” This statement describes which of the following?
a. Broth culture
b. Pour plate
c. Streak plate
d. Dilution plate

Verified video answer for a similar problem:

Key Concepts

Streak Plate Method

Agar Culture Media

Isolation of Microbial Colonies

“In the laboratory, a sterile inoculating loop is moved across the agar surface in a culture dish, thinning a sample and isolating individuals.” This statement describes which of the following?a. Broth cultureb. Pour platec. Streak plated. Dilution plate

Verified video answer for a similar problem:

Key Concepts

Streak Plate Method

Agar Culture Media

Isolation of Microbial Colonies

“In the laboratory, a sterile inoculating loop is moved across the agar surface in a culture dish, thinning a sample and isolating individuals.” This statement describes which of the following?
a. Broth culture
b. Pour plate
c. Streak plate
d. Dilution plate