Detection system

A method for detecting a target nucleic acid sequence in a sample, by subjecting it to an amplification reaction and taking continuous electrochemical measurements on it during the reaction. The method can be used to determine whether an amplification reaction has taken place, to quantitate the amount of target in the sample or to determine sequence characteristics. Also disclosed is apparatus for use in the method, comprising (i) an amplification reaction vessel which comprises an electrochemical cell, (ii) means for taking continuous electrochemical measurements on a sample contained in the vessel and (iii) temperature control and measurement means, wherein the electrochemical cell comprises an element formed from an electrically conducting plastics material such as a polymer loaded with an electrically conducting material. Further disclosed is a reaction vessel for use in the apparatus, a probe for use in the method and a kit for effecting the method.