Question

Which of the following is accurate about the use of ethanol as a lock solution?

1: Ethanol has no known microbial resistance
2: Ethanol has no known effect on coagulation
3: Ethanol has no known effect on biofilm formation
4: Ethanol has no known effect on fibrin deposition

Answer 1

1), A 70% ethanol solution is more effective than a 100% solution for inhibiting microbial growth due to its ability to denature proteins and penetrate cells, unlike higher concentrations which prevent penetration due to rapid protein coagulation on the surface.

Step-by-step explanation:

The question revolves around the effectiveness of different concentrations of ethanol as a lock solution for inhibiting microbial growth. A 70% ethanol solution is typically more effective than a 100% solution because it denatures proteins while allowing for penetration into cells, whereas higher concentrations cause rapid coagulation of surface proteins, blocking further penetration. Ethanol is not sporicidal but it does prevent sporulation and germination. It's widely applied in medical settings as an antiseptic and disinfectant, especially for degerming skin prior to injections and as the active ingredient in hand sanitizers. While effective against a broad range of vegetative microbes, ethanol's volatility limits its effectiveness to right after application, and it may also dry out the skin.