Yours

2.2.3: Bacterial Smear Activity

OER - BIOL 2420 Laboratory Manual · LibreTexts

0%

Contents

    Text

    Size
    100%
    Theme
    Typeface
    Line length
    Spacing

    From LibreTexts, under CC BY 4.0, as the source states it; its equations are written in TeX, which the PDF shows typeset. This page at LibreTexts.

    In this activity you will prepare two bacterial samples for visualization. You will be staining and examining samples that exhibit the two most common bacterial shapes: coccus and bacillus.

    1. Obtain two microscope slides, clean and dry the microscope slides using lens cleaners and Kim wipes
    2. Label the slides using a China marker as seen below:
      Labeled microscope slide showing the specimen circle placed at the bottom of the slide.
      Credit: Sherry Smith

      ***NOTE*** the circle must be placed at the bottom of the slide to prevent the marker from being mixed with the bacterial sample.

    3. Obtain 1-2 loopfuls of bacteria from the appropriate broth culture and introduce the inoculum to the microscope slide, spreading it into a thin film
    4. Allow the slide to air dry completely
    5. Fix the smear passing the air-dried sample 2-3 times through the flame of the Bunsen burner smear side up
    6. Cover the smear with crystal violet for 30-60 seconds
    7. Rinse the slide with DI water
    8. Gently blot the slide to dry it

    Smear Visualization:

    Obtain your assigned microscope. You will visualize your samples using a Total magnification of 400x. Use colored pencils to depict your observations in the spaces below.

    Blank specimen circle for drawing bacterial smear observations.
    Blank specimen circle for drawing bacterial smear observations.

    This page titled 2.2.3: Bacterial Smear Activity was last modified on Sat, 25 Jul 2026 03:43:00 GMT and is shared under a CC BY 4.0 license and was authored, remixed, and/or curated by Sherry Smith.