There is provided a kit of parts for an exhaled breath condensate collection device. The kit comprises a mouthpiece module(100)comprising a breath passageway defined in the mouthpiece module (100) providing fluid conduction from a mouthpiece breath inlet port (122) for receiving exhaled breath to a mouthpiece breath outlet port (124) in use. The kit further comprises a collection vessel (300) for insertion into the device for cooling in use. The collection vessel (300) defines a sealed and resealable chamber for collecting exhaled breath condensate in use. The collection vessel has a vessel breath inlet (326) for admitting exhaled breath into the chamber. The kit of parts is configured such that the collection vessel (300) is: insertable into the device into an sample collection configuration in which the vessel breath inlet (326) is unsealed and in fluid communication with the mouthpiece breath outlet port (124) of the mouthpiece module(100) and removable from the device in a sample containment configuration in which the collection vessel chamber is resealed. One or more parts of the kit of parts is configured and/or operable such that the collection vessel (300) is caused to be resealed into the sample containment configuration after sample collection before the collection vessel (300) is fully removed from the device.
