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+--- Thread: q......? - cilastatin (/showthread.php?tid=629908)
q......? - cilastatin - ArchivalUser - 11-10-2011
with an appropriately performed acid-fast staining procedure, staphylococcus epidermidis will appear
a. Blue
b. Red
c. Purple
d. Colerless
e. Brown
please choose the answer and explain.. thank you
0 - ArchivalUser - 11-10-2011
A. Blue, because Staphylococcus sp doesn't have mycolic acid in their outer membrane (like TB), so the stains can enter (as well as exit) the cell easily.
1st: with carbol fuchsin + heat: red color
2nd: red color is washed out by alcohol: colorless
3rd: stained blue with methylene blue
vs TB
1st: heat is a must to "melt down" mycolic acid to let the carbol fuchsin come inside: red color
2nd: once inside, carbol fuchsin can't be washed out: still red
3rd: without the heat, methylene can't enter the cell: still red.
0 - ArchivalUser - 11-10-2011
aaa
0 - ArchivalUser - 11-10-2011
aaa staphylococcus epidermidis is non-acid-fast