This method for detecting a target nucleic acid sequence involves amplification and detection in the same vessel and comprises: (a) amplification of the target nucleic sequence in a vessel which is provided with a solid phase capture probe comprising a nucleic acid sequence capable of hybridizing to at least a portion of said amplified target nucleic acid sequence, said capture probe being incapable of participating or not participating in standard nucleic acid sequence amplification processes, (b) bringing a sample suspected of comprising said target nucleic acid sequence into contact with said capture probe under conditions which allow said amplified target nucleic acid sequence to be bound by said capture probe, and (c) detecting the presence of bound target nucleic acid sequence. In a further aspect, the present invention provides an assay system or kit, for detecting a target nucleic acid sequence in a sample suspected of comprising said target nucleic acid sequence, comprising: (a) a capture probe comprising a nucleic acid sequence capable of hydridizing to at least a portion of said amplified target nucleic acid sequence, said capture probe being immobilized on a solid phase support which forms a part of or is insertable into a container for the sample, and said capture probe being incapable of participating in standard nucleic acid sequence amplification processes, (b) reagents for amplification of said target nucleic acid sequence, and (c) means for detecting said target nucleic acid sequence, when bound by said capture probe.