Pumping and dispensing culture media, buffer solutions or other fluids are common tasks performed by laboratories worldwide. Making sure that liquids are transferred with high precision and remain free of contamination are key challenges in handling liquids using pumps. Moreover some pump designs, such as those containing valves, are prone to contamination or even jamming when handling certain fluid types such as viscous liquids or suspensions.
These are commonly stated reasons why peristaltic pumps are increasingly becoming the first choice for laboratories tasked with dispensing an array of different fluids.
Peristaltic pumps move the liquid through a flexible tubing (often silicone) by mechanically deforming the tubing. This tube squeezing mechanism called “peristalsis” is a common principle used by many biological systems such as the gastrointestinal tract for moving fluids.
The peristaltic pump was first patented in the United States by Eugene Allen in 1881. However, it took almost half a century to become more popular; thanks to Dr. Michael DeBakey, a world-famous heart surgeon. DeBakey used a peristaltic pump as an essential component for the first heart-lung-machine. This innovation made open heart surgery possible for the first time. Today, peristaltic pumps are used for numerous applications, from filling small test tubes to pumping concrete.
Finding a pump that optimally suits your laboratory liquid dispensing needs is anything but easy as there are many pump suppliers and pump types on the market. In order to make an informed decision, it is important to first establish an understanding of what your requirements are concerning the importance of sterility, the range of fluid viscosities to be handled and of course the precision you require. Knowing about the chemical composition of the fluid to be pumped and dispensed is important too, especially if it is chemically aggressive. Be sure that your pump parts that come into contact with the fluids are compatible – in the case of peristaltic pumps this means carefully selecting the correct tubing material.
In addition to these important considerations – you have to consider who will use the pump and what room is available for it in your lab. Unfortunately a lot of laboratory peristaltic pumps are complicated to program, oversized and bulky.
When selecting a peristaltic pump suitable for your laboratory the following features are attractive:
A particular advantage of peristaltic pumps is that the fluid remains enclosed inside the tubing. As a result, the risk of contaminating either the product or the pump itself is minimized. Moreover, the tubing can easily be cleaned and sterilized after every use. This guarantees sterile conditions and reduces the risk of contaminations. In addition, even chemical aggressive liquids can be transferred without the risk of damaging parts of the pump.
Using a peristaltic pump makes it possible to transfer even delicate liquids such as blood in a way that will not degrade the samples. The gentle rolling mechanism of a peristaltic pump is far less likely to damage blood cells compared to pump designs that use rapid moving propeller blades to move the fluid.
Easy and budget-friendly maintenance
Peristaltic pumps have neither valves nor seals that may be damaged or contaminated by the fluids they have to handle. Consequently, peristaltic pumps require considerably less part replacement compared to other pump designs and maintenance is easier and less expensive.