Konw About Pipette
Pipette, full name called micro pipette, also called pipette gun, sampling gun, is a precision instrument for quantitative liquid volume transfer in the laboratory, which can measure 0.1μL-10mL of liquid at a time, and can achieve accurate liquid proportional transfer, mostly used in environmental testing, medical laboratories, biotechnology laboratories, food testing laboratories, pharmaceutical research laboratories, etc. It is one of the necessary tools for sample collection and pipetting in contemporary biology, chemistry and clinical experiments and other research processes. It is one of the necessary tools for sample collection and transfer in the process of contemporary biological, chemical and clinical experiments, and is mainly used in the sample preparation stage in medical clinical laboratories.
Pipette Working Principle
n short, the basic principle is using the spring to move the piston to achieve the action of absorbing and releasing liquid, but the specific working principle varies slightly from pipette to pipette. Pipettes on the market today can be divided into two main categories according to their principles: exhaust micropipettes and positive displacement pipettes.
Also known as air cushion piston pipettes, the working principle is that the piston moves by spring expansion and contraction and uses air pressure to achieve the action of absorbing and discharging liquid. Under the push of the piston, the pipette expels some air and uses atmospheric pressure to draw in liquid, which is then discharged by the piston pushing the air. This type of pipette is highly accurate and precise, and is suitable for routine pipetting operations. However, this type of air cushion piston pipette has a section of air remaining in the system during the pipetting process, so it is not suitable for aspirating viscous liquids and some volatile liquids.
Positive Displacement Pipettes
This is an external piston type pipette. Unlike exhaust pipettes, the piston of a positive displacement pipette is in direct contact with the liquid, and there is no air cushion separating the piston from the liquid. Because the liquid is in direct contact with the piston without the barrier of an air cushion, this pipette is suitable for pipetting viscous, dense liquids, bubbly liquids and volatile liquids.
In addition to the above two types of pipettes, there are also volumetric pipettes, graduated pipettes, and Pasteur pipettes commonly used in laboratories. Strictly speaking, these three types of pipettes also belong to pipettes, but because of their simple structure, we are generally more used to just calling them transfer pipettes, while the pipettes I generally refer to are the more automated, more accurate, and more complex structure of exhaust micropipettes and positive displacement pipettes.