Microorganisms are spread on the surface of a solid medium using a sterile bent glass rod (disposable sterile plastic rods are now available also). In order to make a spread plate you perform the following steps:
In 1895, French engineer Henry Saint-Rene designed a system of bent glass rods for guiding light images in an attempt at early television.
Watch this informative YouTube video for a visual of this procedure.
Once you have your bent glass rod, you can use it to decorate your glass pieces.
Unformatted text preview: Spread the inoculum on the plate using a bent glass rod that has been dipped in ethanol and passed through the Bunsen burner flame. Be sure to allow the rod to cool before placing it in the inoculum. Keep spreading the inoculum until it has been completely absorbed by the agar. Continue spreading 100 l from each dilution onto the appropriate plate, flaming the glass rod between plates. 9. At the end of 1 hour incubation, remove the HBSS from each well and add 1 ml dH 2 O to wells 1 and 2. Using a p1000 pipetteman, pipette up and down MANY times to lyse the cells, and then transfer the cell lysates to eppendorf tubes. Using wells 1 and 2, we will determine the number of viable bacteria after the second 37 o C incubation. SUB-GROUP 1 Make ten-fold serial dilutions of cell lysate from wells 1 and 2 and inoculate agar plates as described above. SUB-GROUP 2 Observe the cells on coverslips under a microscope. 10. Invert the plates and incubate them at 37 o C for 24-48 hours. Wednesday 11. Count the number of colonies on countable plates (30 to 100 colonies/plate) and calculate the percentage of viable bacteria. # colonies Dilution Well 1 Well 4 % viable bacteria 1:10 1:100 1:1000 1:10000 # colonies Dilution Well 2 Well 5 % viable bacteria 1:10 1:100 1:1000 1:10000 Reading Kuby Immunology 6 th edition Chapter 2 p36-37 Study Questions 1. What is the function of phagocytes in innate immunity? 2. What are two major differences between macrophages and neutrophils? 3. List three receptors that are expressed by phagocytes and induce phagocytosis. 4. How does the acquired immunity help the innate immunity to clear out infections?...