Corrections to last week’s answer

What is the difference between distilled water and sterile water?

V. Barathi

Chennai

The statement “Sterile water is that which inhibits the growth of microorganisms” is incorrect. The correct statement is “Sterile water is that which is devoid of microorganisms due to the process of sterilization (autoclaving).”

If exposed or kept in unclean containers it will lose the sterile nature and will be contaminated. Similarly, distilled water would also be sterile when made but may get contaminated if collected in non sterile containers or when exposed.

No microorganisms generally survives when water is heated to steam and spores or other heat resistant forms would remain at the distilling vessel and will not come up with steam. During condensation if the condenser and collecting vessels are sterile, distilled water would also be sterile water.

The term “distilled” indicates chemical purity and the term “sterile” denotes biological purity.

PROF. G. SUBRAMANIAN

Former Head, Dept. of Microbiology

Bharathidasan University

Tiruchirapalli, Tamil Nadu