Apparatus for controlling and monitoring reactions

An apparatus for heating and optically interrogating a reaction mixture contained in a vessel, the vessel having a chamber for holding the mixture and a port for introducing the mixture into the chamber, the chamber being defined by two opposing major walls and a plurality of minor walls, at least two of the minor walls being light transmissive to provide optical windows to the chamber, the apparatus comprising:

• a) two heating surfaces defined by opposing plates positioned to receive the vessel between the plates such that the plates contact two opposing major walls of the chamber;
• b) at least one heat source for heating the heating surfaces;
• and
• c) optics positioned to optically interrogate the chamber while the heating surfaces are in contact with the two opposing major walls, the optics comprising at least one light source for transmitting light following an excitation path to the chamber through a first one of the light transmissive minor walls and at least one detector for detecting light following a detection path exiting the chamber through a second one of the light transmissive minor walls, wherein the optics are positioned to interrogate the chamber through at least one window or opening between the plates.