A sampling and assay device comprises at least three chamber portions connected together in a row. Each chamber portion defines a chamber separated by respective partitions. One end chamber is capable of receiving a sample. The other chambers contain reagent. In respect of each pair of adjacent chamber portions one of the adjacent chamber portions has the respective partition fixed thereto and the other of the adjacent chamber portions has a rupture member arranged to rupture the respective partition on relative movement of the adjacent chamber portions. Each pair of adjacent chamber portions have respective connection portions mated together, the connection portions being designed to allow further chamber portions identical to an intermediate chamber portion to be connected into said row.