The micropipette was invented in 1957 at University of Marburg, Germany by postdoc Heinrich Schnitger. Frustrated by repetitive pipetting of small volumes using glass micropipettes, Schnitger developed a prototype with a spring-loaded piston and a removable plastic tip for containing liquid.
All the major features of the present-day micropipettes were incorporated into the prototype, shown above, which was patented in 1957. At the bottom of the micropipette a small piston moves in an air-tight bore. Removable plastic tips are fitted to the cone-shaped end. Due to an air buffer, no liquid comes in touch with the piston. The volume is defined by a lower and upper fixed or adjustable stop on the spring-loaded piston. For the complete release of the liquid, increased pressure is applied, which presses down a second spring supporting the lower stop.
Simple, elegant and effective, the micropipette revolutionized handling of small liquid volumes. By enabling rapid micro-volume transfer, it transformed biochemical, medical, molecular and cell biological work and has became the most widely-used device in biological science.
Martin Klingenberg is Professor Emeritus at the Institute of Physiological Chemistry at the Ludwig-Maximilians University, Munich, Germany.