How to Make a Bacterial Smear

Materials and Preparation

• Bunsen Burner: Essential for sterilization, use it daily.
• **Slide Preparation: **
  • Label slide with initials, bacteria type (e.g., Staph aureus), date, and group number.
  • Sterilize loop before starting.

Procedure

1. Water Droplet:

   • Obtain a little bit of water using the beakers.
   • Place one drop of water on the slide using the sterilized loop. Ensure it's just one drop to avoid long drying times.

2. Handling the Bacteria:

   • Use a test tube with the slant facing up.
   • Remove the lid and flame the mouth of the tube to prevent contamination.
   • Hold the test tube at an angle to prevent dust from entering.
   • Cool the loop by touching it inside the tube, then pick up the bacterial cells. It may not be visible on the loop.

3. Applying Bacteria to the Slide:

   • Swirl the bacteria in the water drop on the slide. Be careful not to add too much bacteria.
   • Re-sterilize the loop after applying the bacteria.

Tips for Success

• Avoid Overloading Water: Too much water prolongs drying time.
• Prevent Contamination:
  • Do not speak during the transfer process.
  • Keep flames and tools sterilized at all times.

After Application

• Allow the smear to dry completely before heat fixing.
• Heat Fixation:
  • This step will be demonstrated once the smear is dry.

Common Mistakes

• Too Thick Smears: Make sure to spread bacteria evenly and thinly.
• Talking During Procedure: Increases contamination risk.

This guide provides a step-by-step approach to making a bacterial smear with an emphasis on sterility and proper technique.