Certified Wound Ostomy Nurse (CWON) Practice Test

What should be used to moisten the swab when performing a culture?

1. Sterile saline

2. Hydrogen peroxide

3. Alcohol solution

4. Water

The correct answer is: Sterile saline

The use of sterile saline to moisten the swab when performing a culture is essential because it provides a neutral and non-reactive medium that preserves the viability of the microorganisms being sampled. Sterile saline is isotonic and does not disrupt the cellular structures or cause any damage to the bacteria or fungi that are intended to be cultured. It ensures that the sample collected is representative of the wound site and increases the chances of accurate identification of any pathogens present. In contrast, hydrogen peroxide is antiseptic and can kill bacteria, which would compromise the sample quality by eliminating the very organisms needed for culture. An alcohol solution is also antiseptic and would similarly kill microorganisms, preventing effective culture growth. Lastly, using plain water may introduce contaminants or could lack the required isotonic properties to maintain microbial viability, which is not ideal for the culture process. Thus, sterile saline is the preferred choice for effectively moistening the swab for culture collection.