A valve for a reagent bottle is provided, the valve including a resilient membrane configured to extend across an opening in the reagent bottle, the resilient membrane having at least one slit extending therethrough. Also disclosed is a dispensing apparatus for dispensing a reagent from a reagent bottle, the dispensing apparatus comprising: a probe assembly having a probe adapted for insertion into the reagent bottle through the valve and an extraction mechanism for drawing reagent out of the reagent bottle through the probe. A valve opening assembly is provided, which is adapted to open the valve of the reagent bottle such that the probe can pass through the valve without contacting the valve.