Sterile Water Sample Bottle for Coliform Testing, 120 mL

A water sample for microbiological analysis is only as good as the bottle it arrived in. These come pre-sterilised and sealed, so the container contributes nothing to the count — which is the whole point, because a bottle washed in the laboratory and autoclaved carries a risk that a sealed single-use bottle does not.

Why the thiosulfate matters

The bottle contains sodium thiosulfate, which neutralises residual chlorine the moment the sample is drawn. Without it, chlorine carried in from a treated distribution line keeps killing bacteria in the bottle on the way to the laboratory, and the result reads clean on water that was not. Every drinking-water coliform method requires dechlorination at the point of sampling for exactly this reason.

The 120 mL volume is the standard sample size for the 100 mL aliquot that coliform methods specify, with headspace left for mixing before the aliquot is drawn.

Single use. Do not re-sterilise and re-use: the thiosulfate is consumed and the bottle is not made to be autoclaved.

Fill to the shoulder rather than to the brim, leaving air for inversion, and keep samples cool and in the dark until analysis. Most methods set a holding-time limit measured in hours, not days.