Petri dish streak separation method

Petri dish streak separation method

① Take 1 gram of soil sample, add it to an Erlenmeyer flask containing 99 ml of sterile water beside the flame, block the cotton stopper, and make a bacterial suspension for later use.
②Take a petri dish and place it on the experiment table. [ 90 Mm Sterial Petrie Dishes,Culture Petri Dish,Sterile Plastic Petri Dish,Petri Dish 90 Mm ]Open the petri dish with your left hand. Pour 10-12 ml of melted nutrient solid medium into the petri dish. Gently turn the petri dish to make the culture medium evenly distributed and lay it flat. On the table, make it solidify into a flat plate. Then use crayons to divide the areas A, B, C, and D on the bottom of the dish. [ 90 Mm Sterial Petrie Dishes,Culture Petri Dish,Sterile Plastic Petri Dish,Petri Dish 90 Mm ]Several plates of medium should be made consecutively.
③Fix the bottom of the petri dish with thumb and ring finger in an inclined state, and slightly open the petri dish next to the flame.
At the same time, use a circular inoculation needle to take a small amount of bacteria suspension beside the flame, and quickly send it into the petri dish. On the side of the plate medium, make the first parallel scribing 6-7 lines, and turn the petri dish about 70° For the corners, use a burned and cooled inoculation needle to make the second parallel streak through the first streak part, and then use the same method to make the third parallel streak.
When scribing, make the surface of the plate medium face down to prevent the contamination of bacteria in the air. The inoculation needle should form an angle of about 30° with the surface of the plate. Do not let the inoculation needle touch the edge of the petri dish, and do not scratch the culture medium.
④ Put the streaked petri dish upside down in a warm place at about 28°C. After the bacteria grow, identify the microbial group, and judge whether pure bacteria have been isolated according to the results of the microscopy. If the strain is very pure, it can be transferred to a slant medium for further cultivation. Both the serial dilution separation method and the plate streaking method must be carried out in a sterile room or inoculation box.

Petri dish streak separation method


Post time: Nov-04-2021

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