A cartridge for use with a detection apparatus, the cartridge comprising: a specimen chamber for receiving a sample containing microorganisms; a first detection chamber configured to receive the microorganisms from the specimen chamber and to allow detection of the microorganisms via detection of scattered light from the first detection chamber; a medium comprising a semipermeable membrane between the specimen chamber and the first detection chamber, wherein the semipermeable membrane is configured to permit passage of microorganisms from the sample through the medium into the first detection chamber and to prevent passage of larger components; wherein the specimen chamber and the first detection chamber form separate chambers, the cartridge having walls defining the specimen chamber and the first detection chamber respectively; characterized in that the cartridge further comprises at least one second detection chamber configured to receive the microorganisms from the first detection chamber and to allow detection of the microorganisms via detection of scattered light from the at least one second detection chamber, wherein one or more of the at least one second detection chambers contains a substance potentially capable of inhibiting growth of the microorganisms, the substance comprising an antibiotic, wherein the at least one second detection chamber is configured to be in fluid communication with the first detection chamber, and wherein the cartridge further comprises a transfer mechanism configured to allow a selective transfer of at least part of the sample from the first detection chamber to the at least one second detection chamber. a specimen chamber for receiving a sample containing microorganisms; a first detection chamber configured to receive the microorganisms from the specimen chamber and to allow detection of the microorganisms via detection of scattered light from the first detection chamber; a medium comprising a semipermeable membrane between the specimen chamber and the first detection chamber, wherein the semipermeable membrane is configured to permit passage of microorganisms from the sample through the medium into the first detection chamber and to prevent passage of larger components; wherein the specimen chamber and the first detection chamber form separate chambers, the cartridge having walls defining the specimen chamber and the first detection chamber respectively; characterized in that the cartridge further comprises at least one second detection chamber configured to receive the microorganisms from the first detection chamber and to allow detection of the microorganisms via detection of scattered light from the at least one second detection chamber, wherein one or more of the at least one second detection chambers contains a substance potentially capable of inhibiting growth of the microorganisms, the substance comprising an antibiotic, wherein the at least one second detection chamber is configured to be in fluid communication with the first detection chamber, and wherein the cartridge further comprises a transfer mechanism configured to allow a selective transfer of at least part of the sample from the first detection chamber to the at least one second detection chamber.