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Why do gram positive bacteria retain the primary stain methylene blue while gram negative bacteria are decolorized by rinsing with ethanol?
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∙ 15y ago
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∙ 15y ago
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Will staph grow on EMB agar?
No, it will not. Methylene blue agar is used to identify gram negative bacteria, staphylococcus is gram positive.
Do EMB plate dyes inhibit growth of Gram-positive or negative bac?
The dyes (eosin Y and methylene blue) inhibit the growth of gram- positive bacteria.
Why is methylene blue is an appropriate dye for staining bacterial cells?
It is used in gram staining to differentiate gram negative and gram positive bacteria. After being dyed, the cells are washed with ethanol. Gram positive bacteria will retain the methylene blue due to the amount of peptidoglycan in their cell walls, where gram negative cells will not. Iodine is used as a counter stain, which is up-taken by gram negative cells. After the gram staining procedure is finished, gram positive cells will appear dark purple or blue due to the retained methylene blue. Gram negative cells will appear pink or red due to the iodine counter stain.
What color are gram-negative organisms if you over-decolorized them?
If the Gram Stain is completed properly, gram positive should stain purple; however, if you over decolorize a gram positive organism, the organism will appear appear pink, which is a gram negative reaction. To summarize, if you over decolorize a gram positive organism it will show as a gram negative organism.
Is klebsiella gram positive or negative?
i believe it is a gram bacteria which causes respiratory illness.
Will staph grow on EMB agar?
No, it will not. Methylene blue agar is used to identify gram negative bacteria, staphylococcus is gram positive.
What are the EMB test results for Staphylococcus epidermidis?
The Eosine Methylene Blue test is selective for only gram-negative bacteria. It is possible for gram-positive bacteria to grow, but it would barely grow. Staphylococcus are gram-positive spherical bacteria. So it would not grow on the Eosine methylene Blue Agar.
Do EMB plate dyes inhibit growth of Gram-positive or negative bac?
The dyes (eosin Y and methylene blue) inhibit the growth of gram- positive bacteria.
Why methylene blue inhibits gram positive bacteria?
because it is acidic?
Why do gram positive bacteria do not become decolorized?
the thick peptidoglycan with smaller pores enables gram positive cells to retain the primary dye
Why does gram plus hold onto crystal violet and gram - become decolorized?
Gram positive bacteria have a thicker cell wall.
Methylene blue can be prepared as a basic stain or an acidic stain. How would the pH affect the staining of bacteria?
# The pH will determine if the bacteria will have a particular charge. If the chromophore is a positive ion like the methylene blue in the equation shown in the reading, the stain is considered a basic stain; if it is a negative ion, it is an acidic stain. Most bacteria are stained when a basic stain permeates the cell wall and adheres by weak ionic bonds to the negative charges of the bacterial cell.
Why is methylene blue is an appropriate dye for staining bacterial cells?
It is used in gram staining to differentiate gram negative and gram positive bacteria. After being dyed, the cells are washed with ethanol. Gram positive bacteria will retain the methylene blue due to the amount of peptidoglycan in their cell walls, where gram negative cells will not. Iodine is used as a counter stain, which is up-taken by gram negative cells. After the gram staining procedure is finished, gram positive cells will appear dark purple or blue due to the retained methylene blue. Gram negative cells will appear pink or red due to the iodine counter stain.
What color are gram-negative organisms if you over-decolorized them?
If the Gram Stain is completed properly, gram positive should stain purple; however, if you over decolorize a gram positive organism, the organism will appear appear pink, which is a gram negative reaction. To summarize, if you over decolorize a gram positive organism it will show as a gram negative organism.
What are the positive and negative aspects about bacteria?
The positive aspect about bacteria is that weak bacteria can be used to prevent or defend against other bacteria that harms the body which is the negative aspect of bacteria.
Is klebsiella gram positive or negative?
i believe it is a gram bacteria which causes respiratory illness.
Is anthrax gram positive or negative?
gram positive bacteria
