Typically, most microcapillary pipettes comprise a precision-bored disposable borosilicate or soda-lime glass capillary tube inserted into a small, sealed, dedicated holder, which in turn is fitted at the other end with a rubberised teat or bulb. Capillary action draws fluid into the tube up to the nominal volume, which is then dispensed by squeezing gently on the bulb. The capillary tubes are manufactured to specific diameters and cut to predetermined lengths, so that each one holds a known volume of fluid from end-to-end when filled by capillarity. Other less common types of microcapillary pipette consist of capillary tube with a reusable steel plunger to expel the liquid by positive displacement . Microcapillary pipettes are available in a range of nominal sizes, delivering volumes anywhere from 0.5μL up to 100μL, and can be accurate down to within ±1% of the stated amount. Capillary tubes may also be ring-marked, graduated or colour-coded in some way for ease of identification and selection of the correct size.

What are microcapillary pipettes used for?

• General purpose, micro-volume, precise liquid transfer applications in the laboratory
• In the haematology clinic for applying blood samples onto microscope slides for examination
• Applying sample spots onto TLC plates
• Applying samples to electrophoresis gels