Če se uporabi topilo, mora imeti stalni volumen 1 % (vol./vol.) v vseh kulturah, tj. v negativnih kontrolah in v vseh koncentracijah preskušane kemikalije.
If a solvent is used it must be present at a constant volume of 1 % (v/v) in all cultures, i.e. in the negative controls as well as in all concentrations of the test chemical.