A sample testing assembly 10 suitable for collecting and testing oral fluids such as saliva for a range of tests which could include medical screens, hormonal profiles and drug testing, and particularly tests for illicit drugs. The assembly 10 comprises a sample collector apparatus 12 and a collector vessel 14. The sample collector apparatus 12 comprising a collector member 22 onto which material can be collected, a reservoir part 38 which can contain a supply of liquid, and delivery means for selectively delivering liquid from the reservoir part 38 to the collector member 22 to urge collected material therefrom. The collector member 22 may be at the other end of a handle 16 to the reservoir 38.