Process for closing a means for covering in respect to at least one sample which contains vaporizable fluids, in particular for carrying out a chemical and/or biological reaction, said process comprising at least the following steps: (i) bringing a movable contact area of the means for covering in at least one direction in respect to physical contact with at least one reaction vessel or plate or block containing said at least one sample; (ii) fixating said movable contact area of the means for covering in the position achieved in step (i) by means of engaging at least two matable means for fixating (30, 31) which are capable of fixating the contact area in a plurality of different positions relative to the reaction vessel or plate or block containing said at least one sample in a vertical z-direction, wherein the two means for fixating have the contour of a sequence of a plurality of steps with increasing step height, wherein the means for covering comprises the first and second means for fixating, the second means for fixating being connected to the means for covering, and wherein the at least two means for fixating (30, 31) are moved relative to each other. (iii) applying a pressure/force onto the reaction vessel(s), plate or block in addition to any potential pressure/force applied during the establishing of physical contact in step (i), wherein said application of pressure/force occurs after having performed step (ii) by - using at least one movable element of the means for covering to exert a force/pressure onto the at least one sample and/or at least one reaction vessel or plate or block containing said at least one sample by means of moving the movable element towards the at least one sample or at least one reaction vessel or plate or block containing said at least one sample, or - by using a movable contact area, which is deformable and is part of a containment that contains a fluid material or medium, the hydraulic pressure of which is increased so that the contact area exerts said pressure/force onto the at least one sample and/or at least one reaction vessel or plate or block containing said at least one sample. (i) bringing a movable contact area of the means for covering in at least one direction in respect to physical contact with at least one reaction vessel or plate or block containing said at least one sample; (ii) fixating said movable contact area of the means for covering in the position achieved in step (i) by means of engaging at least two matable means for fixating (30, 31) which are capable of fixating the contact area in a plurality of different positions relative to the reaction vessel or plate or block containing said at least one sample in a vertical z-direction, wherein the two means for fixating have the contour of a sequence of a plurality of steps with increasing step height, wherein the means for covering comprises the first and second means for fixating, the second means for fixating being connected to the means for covering, and wherein the at least two means for fixating (30, 31) are moved relative to each other. (iii) applying a pressure/force onto the reaction vessel(s), plate or block in addition to any potential pressure/force applied during the establishing of physical contact in step (i), wherein said application of pressure/force occurs after having performed step (ii) by - using at least one movable element of the means for covering to exert a force/pressure onto the at least one sample and/or at least one reaction vessel or plate or block containing said at least one sample by means of moving the movable element towards the at least one sample or at least one reaction vessel or plate or block containing said at least one sample, or - by using a movable contact area, which is deformable and is part of a containment that contains a fluid material or medium, the hydraulic pressure of which is increased so that the contact area exerts said pressure/force onto the at least one sample and/or at least one reaction vessel or plate or block containing said at least one sample. - using at least one movable element of the means for covering to exert a force/pressure onto the at least one sample and/or at least one reaction vessel or plate or block containing said at least one sample by means of moving the movable element towards the at least one sample or at least one reaction vessel or plate or block containing said at least one sample, or - by using a movable contact area, which is deformable and is part of a containment that contains a fluid material or medium, the hydraulic pressure of which is increased so that the contact area exerts said pressure/force onto the at least one sample and/or at least one reaction vessel or plate or block containing said at least one sample.