Method for controlling a thermal cycler, and thermal cycler

A method of controlling a thermal cycler to perform polymerase chain reactions, the thermal cycler comprising:

• a sample-receiving thermal block including a temperature measurement device;
• a tempering device thermally coupled to the sample-receiving thermal block and configured to change a temperature of the sample-receiving thermal block;
• and
• an electronic control device comprising a data processing device, the electronic control device being operatively connected to the tempering device and to the temperature measurement device;
• the method comprising:
• receiving, at the electronic control device, tempering schedule data defining a tempering schedule comprising a plurality of temperature steps, the tempering schedule data specifying, for each temperature step of said plurality, a respective temperature value and a respective hold time during which the sample-receiving thermal block is to be held at said temperature value;
• receiving, at the electronic control device, run time data specifying a total run time T for executing the tempering schedule on the thermal cycler;
• determining, by an evaluation program executed on the data processing device of the electronic control device, at least one temperature change rate from the tempering schedule data and the run time data according to the relationship
• T
• =
• Σ
• s
• ⁢
• _heat
• =
• 1
• n
• ⁢
• (
• T_
• ⁢
• {
• S_heat
• }
• +
• Δ_
• ⁢
• {
• S_heat
• }
• /
• r_H
• )
• +
• Σ
• s
• ⁢
• _cool
• =
• 1
• m
• ⁢
• (
• T_
• ⁢
• {
• S_cool
• }
• +
• Δ_
• ⁢
• {
• S_cool
• }
• /
• r_C
• )
• wherein, for each pair of adjacent temperature steps of the tempering schedule, T_{S_heat} is the hold time at a higher temperature level, T_{S_cool} is the hold time at a lower temperature level, Δ_{S_heat} is the temperature difference between said higher temperature level and said lower temperature level, Δ_{S_cool} is the temperature difference between said lower temperature level and said higher temperature level, r_H is a heating rate of the sample-receiving thermal block and r_C is a cooling rate of the sample-receiving thermal block, said heating rate r_H and said cooling rate r_C constituting said at least one temperature change rate;
• determining, by the electronic control device, control parameters defining a tempering control schedule corresponding to the tempering schedule, said control parameters comprising said at least one temperature change rate;
• and
• controlling, by the electronic control device, the tempering device in accordance with said control parameters to execute the tempering control schedule using said at least one temperature change rate, while monitoring the temperature measurement device of the sample-receiving thermal block and adjusting said control parameters in real time so as to maintain said at least one temperature change rate during transitions between adjacent temperature steps of the tempering schedule, said at least one temperature change rate being defined as the difference quotient (T2(t2)−T1(t1))/(t2−t1), wherein t1 is the end of the hold time of a first temperature step at a first temperature T1(t1) and t2 is the beginning of the hold time of a second adjacent temperature step at a second temperature T2(t2).