. Outline the steps involved in an endospore stain (remember smear prep is a par
ID: 135656 • Letter: #
Question
. Outline the steps involved in an endospore stain (remember smear prep is a part of or the Gram stain, what reagents act as the primary which reagents act as the primary stain and counterstain. Understand why endospores ar 8. Why is a dilution series often done before making colony counts? (think along the ines of number why endospores are diffcuit to stain organisms and what you would see on the plate) 9. Be able to recognize a proper streak for isolatio 10. What is the Kirby-Bauer Disk Diffusion Method? What is meant by a "Zone of r plate, be able to measure this. For what reason(s) migh antimicrobial show no zone of inhibition? n and know the purpose of performing this procedure t a chemical that is usually thought to be a good 11. How would you test for the ability of a microbe to produce catalase? 12. What medium is used to test for hemolysis? Why is this an important test in a clinical lab? 13. Be able to identify the following on microscope slides: Gram positive bacteria, Gram negative bactenia. the three basic shapes of bacteria, endospores, negative stain amecium, sample is viewed to " Handout to view these organisms OR you 14. Be able to identify the following on microscope slides: Aspergillus, Penicillium, Euglena, Oscillatoria, Trypanosoma. For the last genus in this list, what type diagnose the infection? Use the "Survey of Microorganisms can view the actual slides on a microscope in the ACE Center (SSB 2201). 15. Know what bacteriophage and viral plaques are; Know howl/why they are related:, Understand why bacteriophage must be grown in bacteria 16. Understand what a plasmid is, and be able to briefly explain how it can be inserted into a bacterium. Know what this process is called. 17. Why can't bacteria be stained using acidic dyes? What are basic dyes? Be able to explain the general concept in terms of the use of these types of dyes on bacteria. Yes we discussed this! 18. Understand how UV light affects bacterial cells and bacterial endospores. 19. Understand the significance of biochemical tests in the identfication of microorganisms 20. Be able to identify an organism using a dichotomous key or a version of the chart you have been using to determine your unknown organisms. 21. Be familiar with the GENERAL lab safety rules. If you follow them, then this should be easy letures posted on CanvasExplanation / Answer
(7)Differential staining technique is used to stain endospores
Preparation of smear and heat fixation
Staining with malachite green (primary stain)
Heating the smear by passing on the flame (heating acts as a mordant)
Wash the smear in running tap water and counterstain with safranin dye
Wash the excess dye, dry it and observe under oil immersion magnification of the microscope to distinguish between the vegetative cells and the endospores.
Endospores are hard structures made of protein coats keratin, hence staining them is difficult.
(8) Serial dilution reduces the number of cells in the given culture by log fold or exponentially.
This reduces the number of colonies that appear on the plates to aid in obtaining countable number of colonies.
(9)In the streak plate method the inoculum is diluted successively by streaking.
The dilution happens to the point that there is only one bacteria deposited every few millimetres on the media. As a result, this isolated bacteria gives rise to a single colony
A well-isolated colony is picked up and re-streaked on to the media plates to obtain pure cultures.
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.