Need help creating flowchart for ID-ing microogranism

Click For Summary
SUMMARY

The discussion focuses on creating a flowchart for identifying the microorganism Micrococcus luteus using various biochemical tests. Key tests include Gram staining, catalase, coagulase, nitrate reduction, oxidase, bacitracin sensitivity, and urease activity. The user seeks clarity on distinguishing between presumptive and confirmatory tests and the appropriate sequence for these tests in the flowchart. The consensus emphasizes the importance of a systematic approach and the use of elimination to deduce the identity of the organism.

PREREQUISITES
  • Understanding of Gram staining techniques
  • Familiarity with biochemical tests for bacteria (catalase, coagulase, etc.)
  • Knowledge of presumptive vs. confirmatory identification methods
  • Basic concepts of flowchart creation and dichotomous keys
NEXT STEPS
  • Research the use of dichotomous keys in microbiological identification
  • Learn the significance of each biochemical test in identifying bacteria
  • Study the process of creating effective flowcharts for laboratory procedures
  • Explore the concept of presumptive and confirmatory tests in microbiology
USEFUL FOR

Microbiology students, laboratory technicians, and educators involved in teaching or learning about microbial identification techniques.

instantresults
Messages
11
Reaction score
1

Homework Statement



I need help creating flowchart for ID-ing an "unknown" organism. Unknown in quotes because I already know ID of organism.

Homework Equations



gram + (purple) tetrads and cocci
forms yellow colonies on NA plate
catalase +
coagulase -
Nitrate +
oxidase (weakly) +
Bacitracin sensitive (+)
Urease +

The Attempt at a Solution



This is for ID-ing an unknown organism which the professor decided to help us out and gave us the organism ID. The organism is Micrococcus luteus I know all the tests but I am confused about two main things:

1.At what point in a flowchart can you say, yes, this is the organism? I'm guessing this has a lot to do with a presumptive ID, and then a confirmatory ID. But how does one know when you reach that point? Also we never went over the idea a "dichotomous key" but does a dichotomous key help out a lot in flowchart creation?

2.How do I know if I have the correct sequence in the flowchart I am creating, and also, which test is considered presumptive and which is confirmatory?

I obviously started with the gram stain, which gave me purple tetrads. Then I did the catalase test; got bubbles = positive. Next I did the coagulase and it did not clot: = negative. But the next step is confusing me: there are multiple tests I could do, but which tests will differentiate the most?

Also I know what each test is testing for and its implications for ID-ing (I think I do anyway) and I can provide details if that helps in answering question (so you know that I know I mean). This is undergrad intro to microbio, so the test are pretty common and not that techincal.

Thanks for any help at all really appreciate it
 
Physics news on Phys.org
Why he didn't just give you the flowchart and ask for you to find it based off the results is beyond me. You need to perform all the tests in order to deduce the identify of your microbe. You can find the microbe using elimination of the other results, which species it could not be and what not. There is no point in creating a flow chart for one species of bacteria. You will have to redo your experiments. I would say he helped you all out too much, because the purpose of the exercise isn't clear after being given the answer. You will need to pretend you don't know the answer already, go through and find the microbe based upon the new results from the experiments. Is this an online course or something?

clip_image006_thumb21.jpg

http://www.yourarticlelibrary.com/e...cation-of-unknown-bacteria-with-figure/26632/
 

Similar threads

Advanced Molecular Biology - HELP NEEDED
  • · Replies 1 ·
Replies
1
Views
5K