Definition
A refrigerated low-speed centrifuge is a type of laboratory equipment that combines temperature control with low-speed centrifugation. It is capable of separating, precipitating, or concentrating samples at relatively low rotational speeds in a low-temperature environment. These devices are typically suitable for biological samples or chemicals that are sensitive to temperature and require the avoidance of high-speed shear forces.
Principle
The working principle of a refrigerated low-speed centrifuge is based on the synergy of centrifugal force field and temperature control. As the rotor rotates, the sample is subjected to centrifugal force, and components of different densities or sizes settle along the radial direction to achieve separation. The centrifugal force follows the following relationship:
F = m × ω² × r
where F represents the centrifugal force, m is the mass of the sample, ω is the angular velocity, and r is the radius of rotation. At the same time, the device's built-in refrigeration system maintains the chamber temperature within a set range (typically -20°C to 40°C) during operation to protect sample activity.
Measurement method
When operating a refrigerated low-speed centrifuge, key parameters are measured including speed, temperature, and time. Rotational speed is typically expressed in revolutions per minute (rpm) or relative centrifugal force (rcf), which provides a more accurate reflection of the actual separation force. The temperature is monitored in real time by sensors in the chamber and fed back to the control system. Time control relies on precise timing modules to ensure that the separation process is completed within a set duration. Users need to set and calibrate these parameters appropriately according to the characteristics of the sample and the separation goals.
Influencing factors
The separation effect of a refrigerated low-speed centrifuge is affected by a variety of factors. The rotor type and capacity determine the loading method and centrifugal force distribution of the sample. Temperature stability directly affects sample activity preservation, and cooling efficiency and uniformity are key. The setting of rotational speed and acceleration/deceleration curves can affect the resolution and sample integrity. In addition, the viscosity and density differences of the sample, as well as the low temperature resistance of the tubing, also play a role in the results.
Application:
Refrigerated low-speed centrifuges are widely used in many fields. In biological research, it is commonly used for cell collection, protein precipitation, and subcellular component separation. It can be used in the food industry for fat separation or composition analysis. In the field of environmental detection, it is used for suspended solids concentration or microbial collection. Its low-temperature properties make it particularly suitable for handling thermally unstable substances such as enzymes, vaccines, and sensitive biochemical reagents.
Selection
When choosing a refrigerated low-speed centrifuge, it is necessary to comprehensively consider the technical parameters and usage requirements. The temperature range and temperature control accuracy should meet the sample preservation requirements. The maximum capacity and rotor configuration should be adapted to the scale of the conventional experiment. The speed range should cover the required range for low-speed separation. Safety features such as lid locks, imbalance detection, and over-temperature protection are also noteworthy. In addition, operating noise, energy consumption and ease of maintenance are also important considerations in long-term use.