Role of Magnetic Stirrer to Conduct Biological and Chemical Experiments

Magnetic Stirrer was first patented by Richard Stringham in the year 1917, in Utah. It consisted of Stationary electromagnets inbuild into a hot-plate base, and therefore when the flask or beaker was positioned on the stirrer, a magnetic bar immersed inside the solution rotates due to the magnetic field affected by the electromagnets. Although even after centuries of technological advancement, the original design of the Stirrer remains to dominate the agitation and stirring processes. However, the introduction of a Hotplate Magnetic Stirrer was a tremendous success in laboratory automation. In Hotplate Magnetic Stirrer, a hot plate is used for heating the liquid mixture under the required conditions for mixing purposes.

What is Magnetic Stirrer?

A Magnetic Stirrer is a Laboratory device, that uses a rotating magnetic field to rotate a stir bar. the movement of the stir bar mixes the sample thoroughly with rapid movement and agitation. However, to avoid reactions with the magnetic field, these stirrers are used with glass or other non-metal beakers. Also, the magnetic stirrer holds technical parameters that precisely control the temperature of the hot plate, speed of the rotation, and time duration of the stirrer device. Therefore, configuring a magnetic stirrer with hot plates improves the production of uniform mixes and also heats the sample simultaneously.

Principle of Magnetic Stirrer

The Magnetic Stirrer operates on the principles of, attraction for unlike charges and repulsion for like charges. As the magnetic device is ready to function, the heating mechanism and electromagnetic effects are activated with the temperature, speed, and time set. The key purpose of the magnetic stirrer is to generate a magnetic field to stir solvents of various viscosities. A micromotor drives a magnet to generate a magnetic field to stir the bar in the vessel resulting in the proper mixing of the solution. The liquid sample rotates along with the magnetic bar during the stirring process. For efficient mixing, the vessel along with the magnetic bar is placed at the center of the plate regulated by a temperature-controlling knob that heats the solution simultaneously.
The magnetic stirrer motor works on two main principles, a stirring mechanism, and control electronics. A motor movement with a magnet on top causes the rotation of stir bars to mix the liquids, whereas, control electronics supervise motor RPM and keyboard functions. These stirrers are designed for mixing liquids of varied viscosity by rotating or oscillating processes at great speed.

A magnetic stirrer is commonly used in microbiology laboratories for the purpose to prepare a medium for cultivating bacteria. It is also used in chemical experiments and synthesis involving the combination of two or more components. Various other applications, such as oil analysis, soil suspension, buffer solution production, and pH testing. Altogether in general, it is used for sample preparation and analysis in laboratories.

Advantages & Limitations of Magnetic Stirrer

Advantages	Limitations
Easy to Operate Compared to other Mechanical Stirrers	The size of the Stir Bar needs to be changed frequently due to the nature of the solution mixture.
Samples can be mixed for several hours or even overnight stirring while operating a magnetic stirrer with a hot plate.	The device can only be utilized for small-scale experiments due to its compact size.
Easy to clean and sterilize the magnet due to its compact size, therefore, reducing the possibility of contamination.	It is not ideal to stir viscous, dense, or large-volume suspension of liquid.
Magnetic stirrers are more versatile than electronic stirrers in terms of performance and precision.	Can't be operated at extremely high temperatures, because the exterior covering of the stir bar might deteriorate under such conditions.
Ideal for mechanical stirrers and lengthy operations such as protein dialysis.
Allows the mixing of regents at a steady temperature at varied speeds.

Magnetic Stirrer operating procedure

While operating a magnetic stirrer with a hot plate, ensure the working area and sensors are sanitized, clean, and free from debris and excessive moisture. Prepare a container with the liquid solution and place it on a hot plate to power the device. Adjust the temperature setting and set the button clockwise to change the speed of the magnetic stirrer. Also, turn the magnetic stirrer to adjust the knob if the speed is too high. Stir the mixture continuously until uniformity is achieved.

Precaution Measures while Operating Magnetic Stirrers

• Laboratory instruments should be properly grounded to avoid accidents and mishaps.
• To avoid excessive vibration while operating, run the operation at medium speed for eight hours and then at high speed for four hours.
• Turn off the power when not in use, and keep it dry, clean, and ventilated space.
• Always check the position of the beaker placed correctly to avoid beating instead of stirring
• Prohibit the solution flows into the machine to avoid damage to the stirring device
• Avoid stirring for a prolonged time therefore intermittent use can extend the life cycle
• Additionally, magnetic stirring can be used with any chemical substance.

Bottom Line

Magnetic Stirrer is one of the widely used laboratory equipment used in scientific research and industrial production. Biolab offers excellent stirring performances, easy to operate and maintain at the same time. Therefore, magnetic stirrers are primarily used in Chemical and Biological experiments for sample preparation and analysis. The core function of these stirrers is to agitate liquid samples to speed up the reaction process or enhance the mixture.

The capacity of the liquid in the flask or beaker, the degree of oscillation, the speed of rotation, and the heating temperature are considered while choosing the right magnetic stirrer for your facility. Get in touch to know more about essential laboratory and Industrial equipment for your facility. Biolab has a complete range of Laboratory equipment that is up to industrial standards and use.