Abstract: A method for rapid thermal control of a reaction volume from a preceding temperature to a target temperature includes first bringing at least the reaction vessel's second wall, which has high thermal conductivity, into direct contact with a first thermal block at a temperature higher than the target temperature if the target temperature is higher than the preceding temperature, or at a temperature lower than the target temperature if the target temperature is lower than the preceding temperature, until the reaction volume temperature is at least close to the target temperature; and then bringing the second wall into direct contact with a second thermal block at the target temperature. Also disclosed is a system (20) for detecting and/or quantitating a biological and/or chemical analyte in a sample and a software product for the system.