BISC209: Preparing a bacterial smear slide

Preparing a bacterial smear slide

Preparing a bacterial smear slide is useful for microscopic examination of dead bacterial cells.
1. Place a very small loopful of water on the slide first (use the deionized water bottle on your bench-remove the cover and dip your loop in – sterility is not required for this step).
Note: If the bacterial smear is being made from a broth, simply place a loop or two of the broth culture on the slide and spread as above do not use additional water.

2. Flame the loop, cool and touch it to the colony or slant growth and place the now contaminated loop into the drop. Use large circular motions to spread the drop to about the size of a quarter over the slide. 3. Reflame the loop.

4. Allow the smears to air dry.

5. Heat fix (kill and attach organisms to slide) by rapidly passing the slide (smear side up) through a flame 3 times. Use a slide holder and avoid contact with hot glass.