Process for preparing a cell suspension

A process for carrying out an in vitro biochemical reaction for preparing a cell suspension suitable for application to the skin of a patient, the process comprising:

• i) activating a warmer, the operation of which is based on an exothermic physical or chemical process,
• ii) bringing said warmer into contact with a container containing a solution comprising trypsin by placing the warmer and at least the lower part of the container in a cavity of a support,
• iii) placing a skin tissue sample comprising cells suitable for grafting to the skin of the patient in the solution comprising trypsin and incubating at from 30° C. to 40° C. for at least five minutes, and
• iv) isolating cells disassociated from the skin sample and suspending the cells in a solution, to thereby provide a cell suspension suitable for application to the skin of a patient.