In microbiology laboratory procedures, what is the primary purpose of using a sterile spreader?

• A. To sterilize the surface of the agar before inoculation
• B. To measure the turbidity of a liquid culture
• C. To transfer colonies from one plate to another
• D. To evenly distribute microorganisms across the surface of an agar plate

Answer: (D)

Verified step by step guidance

1. Understand the role of a sterile spreader in microbiology: it is a tool used during the plating process to distribute microorganisms evenly on the surface of an agar plate.
2. Recognize that sterilization of the agar surface before inoculation is not the purpose of the spreader; agar is typically sterile before use.
3. Note that measuring turbidity of a liquid culture is done using a spectrophotometer or similar device, not a spreader.
4. Understand that transferring colonies from one plate to another is usually done with an inoculating loop or needle, not a spreader.
5. Conclude that the primary purpose of a sterile spreader is to evenly distribute microorganisms across the surface of an agar plate to ensure isolated colony growth.