A closed measuring cell for carrying out chemical and biochemical analyses, the cell comprising: a cylindrical vessel having a bottom and outer wall having a measuring window transparent to light; and a piston being capable of moving up and down inside the cylindrical vessel in a change from an initial preparedness position to measuring position and containing reacting components in dry stage needed to carry out the analyses of a sample, the cylindrical vessel having a liquid reservoir and a waste reservoir at the bottom of the vessel and the liquid reservoir and waste reservoir being separated from each other by a vertical wall and the liquid reservoir is filled with a washing reagent needed to perform the analyses of a sample, wherein in measuring position the liquid flows through holes in piston into the waste reservoir; the liquid reservoir filled with the washing reagent is sealed in the preparedness position by a membrane; the piston containing an active surface area and in the initial preparedness position a sample to be analyzed can be introduced through a hole onto the active surface where reaction of the sample take place; and an extension of piston locks the liquid reservoir when the piston is at the measurement position; when the measuring cell is changed from the initial preparedness position to the measuring position by pushing the piston inside the cylindrical vessel, the tip of the piston protrudes into the liquid reservoir and the piston replaces liquid in the liquid reservoir while the washing reagent in the liquid reservoir erupts off onto the active surface and the active surface is washed with washing reagent and a measureable signal created by reaction on the active surface area can be measured through the window of the outer wall where measurement signal is proportional to amount of an analyte in the sample. a cylindrical vessel having a bottom and outer wall having a measuring window transparent to light; and a piston being capable of moving up and down inside the cylindrical vessel in a change from an initial preparedness position to measuring position and containing reacting components in dry stage needed to carry out the analyses of a sample, the cylindrical vessel having a liquid reservoir and a waste reservoir at the bottom of the vessel and the liquid reservoir and waste reservoir being separated from each other by a vertical wall and the liquid reservoir is filled with a washing reagent needed to perform the analyses of a sample, wherein in measuring position the liquid flows through holes in piston into the waste reservoir; the liquid reservoir filled with the washing reagent is sealed in the preparedness position by a membrane; the piston containing an active surface area and in the initial preparedness position a sample to be analyzed can be introduced through a hole onto the active surface where reaction of the sample take place; and an extension of piston locks the liquid reservoir when the piston is at the measurement position; when the measuring cell is changed from the initial preparedness position to the measuring position by pushing the piston inside the cylindrical vessel, the tip of the piston protrudes into the liquid reservoir and the piston replaces liquid in the liquid reservoir while the washing reagent in the liquid reservoir erupts off onto the active surface and the active surface is washed with washing reagent and a measureable signal created by reaction on the active surface area can be measured through the window of the outer wall where measurement signal is proportional to amount of an analyte in the sample.