A method, an extraction instrument and a dispensing instrument for pretreating, in particular, a biological sample for, in particular, molecular-biological testing of the sample, the extraction instrument being sealed or able to be sealed by means of compression, and/or the sample being introduced or able to be introduced into the dispensing instrument through a piston of the dispensing instrument and/or being filtered or able to be filtered in the dispensing instrument. Furthermore, a kit for pretreating, in particular, a biological sample for, in particular, molecular-biological testing of the sample which includes a receiving instrument for receiving the sample, an extraction instrument, a treatment agent for treating the sample and a dispensing instrument.