Staining Flashcards
Gram stain procedure
Crystal violet - grams iodine - decolorizer - safarin
Gram variability (cause)
In old cultures peptidoglycan layer shrinks (clostridium / some bacillus) - bacillus endospore also appear gram neg due to capsule In some species cells wall can break off during division to give a false negative because no peptidoglycan remains (propionibacterium / corynebacterium)
Catalase
Identify staphylococcus
Coagulase
Differentiate Staph aureus and other staph species
MALDI-TOF (stands for)
Matrix assisted laser desorption/ionizations - time of flight aka time of flight mass spec identification Time of flight is the measurement procedure for the ionization caused by the lazer
MaConkey’s Agar growing….
![](https://s3.amazonaws.com/brainscape-prod/system/cm/158/312/901/q_image_thumb.jpg?1441908818)
E. coli (or any lactose fermentor)
MaConkey’s Agar growing…
![](https://s3.amazonaws.com/brainscape-prod/system/cm/158/313/264/q_image_thumb.jpg?1441908930)
Non lactose fermentor
Cetrimide agar growing…
![](https://s3.amazonaws.com/brainscape-prod/system/cm/158/314/684/q_image_thumb.jpg?1441909320)
Pseudomonas aeruginosa
m-Endo growing..
![](https://s3.amazonaws.com/brainscape-prod/system/cm/158/314/856/q_image_thumb.jpg?1441909437)
Coliforms (metallic sheen)
Mannitol salt growing…
A) Yellow
B) White
A) Staph aureus - ferments the mannitol -> ph changes phenol red
B) Staph epidermidis