Patent ID: 7504264

Claim:
A method for characterizing highly parallelized liquid handling technology, preferably for volumes in the μl range and sub-μl range, using microplates, wherein the liquid handling technology has a large number of elements for sample handling, such as multipipettes, by which a large number of sample volumes of a sample liquid or reagent liquid are placed in wells of a microplate that are arranged in grids for preparation and analysis or storage and transport, etc., of samples in many channels with determination of volumes by gravimetry and optical measurement in the presence of a diluent, comprising the steps of: determining a mean sample volume or mean reagent volume with respect to the number of channels of the liquid handling technology by gravimetry under conditions of greatly reduced evaporation from all of the sample volumes or reagent volumes that are dispensed simultaneously into the wells of the microplate by the liquid handling technology to be characterized; mixing every sample volume and reagent volume, each containing a first indicator with specific optical characteristics and at least one second indicator with optical characteristics differing from those of the first indicator for purposes of optical measurements, with a diluent which contains the same at least second indicator in a concentration identical to that of the sample volume or reagent volume but which does not contain the first indicator; generating at least one first optical measurement signal caused by the first indicator and, in the same way, a second optical measurement signal caused by the second indicator for each well of the microplate that is filled with a mixture of the sample volume or reagent volume and diluent; normalizing every first optical measurement signal with respect to its intensity by the at least second optical measurement signal of the associated well of the microplate for purposes of error compensation, particularly for eliminating influences of the well geometry, the shape of the liquid surface in the well, the blank absorbances, etc.; forming a mean optical intensity value which is normalized with respect to the quantity of channels of the liquid handling technology to be characterized from all normalized optical measurement signals and the intensity deviation of the corresponding normalized optical measurement signal from the normalized mean optical intensity value is acquired for every well of the microplate; and determining the volume of every channel of the liquid handling technology to be characterized with reference to the mean sample volume or mean reagent volume determined by gravimetry from the intensity deviation of the corresponding normalized optical measurement signal in relation to the mean optical intensity value.