Very thin and flexible glass fibre-needles, which are extremely flexible and sturdy by their special coating. The coating as well as the glass are resistent against most solvents, acids and alkaline solutions. It is possible to manufacture needles with diameters of less than 100 µm. The end of the fibre is embedded in a Luer-connector, made of Macrolon, and enables the use of normal standard-tips and pumping systems.