Inoculations
Streak plate (Cappuccino & Welsh, 2017). Refer to Figure 12. Using aseptic technique:
- Using a Sharpie marker, divide the plate into 4 quadrants labeled 1-4 clockwise.
- Flame transfer loop and cool. Place a loopful of broth culture in quadrant-1 by dragging the loop across the periphery (close to the edge of plate) in a tight
zigzag pattern. - Flame loop and cool. Turn plate 90° Touch the loop at one corner of quadrant-1 and drag across to quadrant-2 in a similarly tight zigzag pattern.
- Flame loop and cool. Turn plate 90° Touch the loop at one corner of quadrant-2 and drag across to quadrant-3 in a similarly tight zigzag pattern.
- Flame loop and cool. Turn plate 90° Touch the loop at one corner of quadrant-3 and drag across to quadrant-4 and up through the middle/center of the plate, carefully avoiding previously inoculated areas in quadrants 1-3.
- Remember to store plates upside down: tape the lid to the plate; store it with the lid on the bottom. This allows for any condensation to drip onto the lid instead of on the medium/culture itself.
Figure 12. Streak plate technique
Reference
Cappuccino, J. G., & Welsh, C. (2018). Microbiology: A laboratory manual.
