Nutrient agar plates
24-hour broth culture of Staphylococcus epidermidis
Six-day-old culture of Bacillus subtilis
With your marking pencil, section an agar plate into two parts.
Streak the S. epidermidis culture on one-half of the plate. Label this section Control.
Sterilize the loop, take another loopful of S. epidermidis culture and sterilize the loop again in the Bunsen burner flame or
bacterial incinerator. When the loop is cool, use it to streak the second half of the plate. Label this section Heated.
Repeat procedures 1 to 3 with the B. subtilis culture.
Incubate the plates at 35°C for 24 hours.
Read for growth (+) or no growth (−) and record.