Method for optically examining small amounts of liquid using a cuvette and insert parts that form a column of liquid between two measuring areas

#Not applicable.

#The present invention is related to the analysis of liquid samples with a spectrometer or photometer or other optical measuring devices. Such analyses are made typically, but not exclusively, in the molecular-biological, biochemical, inorganic-chemical, and organic-chemical and foodstuff chemical laboratory. Samples are optically analysed for instance in research, in diagnostics and in quality control. They are analysed for instance by way of absorption-, reflection-, emission-, fluorescence-, Raman- or luminescence spectroscopy in the UV-VIS or IR wavelength range. Examples for analytes to be measured are biomolecules like nucleic acids, proteins, lipids as well as inorganic or organic materials and compounds. These analytes can be measured directly or after a chemical reaction that serves for facilitating the spectrometric or photometric analysis.

#The present invention is related in particular to all the applications that were mentioned by way of example above. An essential field of its application is the measurement of valuable samples in small amounts in molecular biology. Often only small amounts of sample are at hand (for instance, from less than 1 up to 5 micro-liters), because nor more material can be obtained. When diluting the samples, the measurement results would become too inaccurate due to decreased absorption. A typical application is the photometric or fluorometric measurement of nucleic acid concentrations before a PCR or real-time PCR, in order to be able to use that starting amount of the nucleic acid which is optimum for PCR. Another example is the measurement of the concentration of nucleic acids and marker substances incorporated into the nucleic acid, as well as of the marking density of marked nucleic acids derived from this, in order to be able to use the optimum amount of marked nucleic acid before beginning a micro array experiment, and to be sure that the marking density of the nucleic acid is in the optimum range.

#In the drawings shows:

#FIG. 1 a pincette with planar measuring areas at the free ends and opened arms, in a perspective view slantwise from the side;

#FIG. 2 the same pincette with arms swung together, in the same perspective view;

#While this invention may be embodied in many different forms, there are described in detail herein a specific preferred embodiment of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiment illustrated

#In the following, the designations “upside” and “downside” refer to that orientation which the corresponding parts of the device have when they are arranged in a cuvette shaft of a photometer or spectrometer.

#The cuvette shown in FIGS. 1 to 4 consists of at least two parts.