Sodium thiosulfate is put into bacteriological sample bottles to sterilize the water.

Sodium thiosulfate is put into bacteriological sample bottles to sterilize the water.

• A. True
• B. It sterilizes the water
• C. It preserves the sample
• D. False

Answer: (D)

The main concept is dechlorination in bacteriological sampling. Sodium thiosulfate is added to sample bottles to neutralize residual disinfectants like chlorine that are still present after collection. By stopping the ongoing antimicrobial action of these oxidizers, it prevents them from killing or inhibiting bacteria during transport and testing, which could otherwise lead to falsely low counts. It does not sterilize the water, and it’s not a preservative—the goal is to prevent interference from chlorine, not to preserve or sterilize the sample.

The main concept is dechlorination in bacteriological sampling. Sodium thiosulfate is added to sample bottles to neutralize residual disinfectants like chlorine that are still present after collection. By stopping the ongoing antimicrobial action of these oxidizers, it prevents them from killing or inhibiting bacteria during transport and testing, which could otherwise lead to falsely low counts. It does not sterilize the water, and it’s not a preservative—the goal is to prevent interference from chlorine, not to preserve or sterilize the sample.