Cameron Martins Amazing Review Rated RNo child under 17 will be permitted with out a adult
Lab one• Special Media: The two other types of media you will see in class today are enriched and selective/differential. Enriched media is used to culture fastidious organisms like Streptococcus pyogenes. The example in the laboratory is blood agar which contains 5% sheep blood.• Selective media allows for some bacteria to grow and inhibits others. Differential media allows bacteria to grow based on some biochemical or physical property that allows the bacteria to be differentiated from each other.
Lab two Streak plate technique• This uses distance to dilute bacteria out• Uses a inoculating loop to spread to dilute.
Lab 3• Hanging Drop Slide This slide is used to detect motion of the bacteria.• Negative stainingDoes not stain the bacteria it stains the background. This stain is acidic.(ex nigrosin) Simple StainingWill stain the bacteria, this stain is basic. (ex. Crystal violet)
Lab 4• Gram stainStains the cell wall of the organism this tells the type of cell wall of the organism.Red cells gram – purple gram positive.• Capsule stainThe maneval stain was used this told if the organism had a capsule uses a negative stain to coat the outside of the cell. A capsulated cell would have a clear space between the two stains.Endospore stainThis procedure you cooked in malachite green stainFor 5 min. then counter stain with safranin.The red is vegetative cells and the green is endospores.
EMB• A positive test means what ?• growth of Gram - organisms. Additionally, the medium contains lactose which can be utilized by lactose fermenters as a carbon and energy source.• Grow means its what ?• That it’s a gram -.
Macconkey’s• What does growth mean ?• That is a gram -• What does positive test mean?• Like EMB, this medium contains lactose and those organisms that can utilize lactose produce acids. The acid production results in a lower pH in the medium and a change in the color of the medium to yellow. Neutral red is the ph indicator• This also has peptones in the media if it turns pink it means that the organism is breaking down peptones.• The selective molecule is bile salts
Hektoen enteric agar• MacConkey’s agar. However, this differs from MacConkey’s agar because it also has ammonium sulfate and sodium thiosulfate in it.• These chemicals are indicator molecules because they react with H2S released from the breakdown of peptones in the medium and turn the H2S producing colonies black (indicating that H2S was present).• The pH indicator in this medium is bromothymole blue.• When bacteria use the lactose and sucrose in the medium acid is produced and the medium’s color changes from a blue/green• It has bile salts as the selective indicator molecule
Mitis-salavarius• Grows up mainly gram positive mainly streptococcus.• It incorporates the trypan blue from taking in sucrose peptones and all the different carbohydrates.• This media incorporates crystal violet and potassium tellurite which inhibits gram negatives, and other non streptococcus organisms.
Mannitol salt agar• IF an organims grows this means that the organism is a halophile.• .When the organism uses mannitol it changes the PH of the media changing it yellow• PH indicator phenol red• It has NaCl as a inhibitory molecule.