Thermal cycler

An automatic analytical device, which comprises:

• (a) a plurality of test tubes, each for containing a predetermined volume of a liquid reaction mixture, each of the plurality of test tubes being equipped with a pierceable closure;
• (b) a pipetting needle configured and dimensioned for piercing the pierceable closures and removing liquid reaction mixture from the test tubes;
• (c) means for moving the pipetting needle from a position outside of each test tube, through the piercable closure on the test tube, and into the test tube;
• (d) means for applying suction to the pipetting needle so as to enable the pipetting needle to withdraw liquid reaction mixture out of a given test tube when the pipetting needle is inside the given test tube and reaction mixture is present within the given test tube;
• and
• (e) a device for automatic performance of temperature cycles on the test tubes, which comprises:
• (1) a holder formed of a thermally conductive material and having an upper surface, a lower surface and a cylindrical outer wall, the holder having an array of chambers for holding the test tubes equipped with piercable closures, the chambers being disposed along an arc with each chamber having an opening located in the upper surface of the holder, each chamber being configured and dimensioned to receive one test tube equipped with a piercable closure, the holder being configured and dimensioned so that when test tubes having piercable closures are held in the array of chambers, the piercable closures of the test tubes can be accessed by a pipetting needle;
• (2) a computer-regulated automatic control system;
• and
• (3) means actuated by the automatic control system for cyclic alteration of the temperature of the holder.