Method for thermally cycling samples of biological material with substantial temperature uniformity

A method for thermally cycling samples of biological material comprising:

• inserting a plurality of samples of biological material into a thermal block assembly;
• measuring the temperature of the thermal block assembly at at least one location on the thermal block assembly;
• comparing the measured temperature of the thermal block assembly with a desired temperature;
• heating the thermal block assembly with a first heat source;
• heating the first heat source with a portion of the heat from a second heat source;
• heating the thermal block assembly with a portion of the heat from a third heat source;
• and
• repeating the steps of measuring, calculating, and comparing until completing a predetermined thermal cycle for the samples of biological material.

A method for thermally cycling samples of biological material in an apparatus with at least one sample holder located in a thermal block assembly comprising:

• inserting at least one sample of biological material into a sample holder of the apparatus;
• measuring the temperature of the thermal block assembly at multiple locations;
• calculating the desired temperature of the thermal block assembly;
• comparing the desired temperature with the measured temperature, and if the measured temperature is less than the desired temperature, the method further comprises:
• applying a first heat source, a portion of the heat from the first heat source being transferred to the thermal block assembly;
• applying a second heat source, a portion of the heat from the second heat source being transferred to the first heater;
• and
• applying a third heat source, a portion of the heat from the third heat source being transferred to the sample holders;
• if the measured temperature is greater than the desired temperature, the method further comprises cooling the thermal block assembly by imparting a cooling convection current on a heat sink which is thermally coupled to the thermal block assembly to provide heat transfer from the thermal block assembly to ambient air in contact with the heat sink;
• and
• repeating the steps of measuring, calculating, and comparing until the predetermined thermal cycle for the samples of biological material is completed.