Horizontal Rotor Centrifuge are divided into three categories: horizontal rotors, fixed-angle rotors and vertical rotors. Each category aims to solve three key factors: 1) centrifuge basket type (differential centrifugal, rate zone centrifugal or isodensity centrifugal), 2) velocity and 3) volume range.
What is the difference between horizontal and fixed centrifuge?
Tubes centrifuged in a horizontal Centrifuge Basket experience a larger radius, resulting in a higher RCF and more efficient forces. Higher g-forces produce a better seal with the tube wall due to better gel packing. The time required for complete centrifugation is only 2/3 of the time required in a fixed-angle centrifuge
Horizontal Rotor Centrifuge:
Also known as shaking off the rotor (flattening or swinging the barrel rotor). When the rotor is stationary, the center line of the centrifuge in the rotor is parallel to the rotating axis. When the rotating head is rotated and accelerated, it is thrown from the vertical position to the position at a 90° angle to the rotating axis by the action of centrifugal force, and the sample is concentrated at the bottom of the centrifuge.
Fixed-angle rotor:
The angle rotor is the most common rotor used in Basket centrifuge. As the name implies, there is a certain angle between the centrifuge tube and the shaft of the rotor, and the angle range is usually between 14°-45°. It is mainly used to separate particle samples with significant differences in sedimentation rates. The particles move at a short distance in the fan-shaped solution. The particles that touch the outer wall slide along the pipe wall to the bottom of the tube to form precipitation, so this rotor can quickly collect sediment. This kind of rotor has a low center of gravity, long life, high rotation speed, and a high maximum centrifugal force, up to 800,000×g. The horn rotor is mainly used for differential separation, precipitation of particles from suspension or collection of particles. The volume of the cavity in these rotors ranges from 0.2mL to 1L, and the speed ranges from single digits to 1,000,000×g (RCF, relative centrifugal force).
The most common angle rotor is the fixed angle rotor, which has a low center of gravity, small resistance, stable operation, and is suitable for high-speed separation. However, the fixed-angle rotor should not be separated in large capacity, because when the particles settle, they first hit the centrifuge tube in the direction of centrifugal force, and then slide to the bottom of the tube along the wall of the tube. Particle deposition will appear on one side of the tube, resulting in the wall effect, which will affect the separation effect.
How to match the angle rotor with the micro high-speed centrifuge?
For micro-high-speed centrifuges, the common angle rotor single tube capacity is 1.5mL, 2mL, 5mL and PCR tubes.
Reward micro high-speed centrifuge (normal temperature/freezing) has added an airtight fast-lock rotor compatible with 5mL centrifuge, which can not only be sterilized by high temperature, but also equipped with a fast-lock rotor cover design. It only needs to rotate 1/6 times to lock quickly, which is convenient for sample collection. Of course, we can also match the airtight quick-locking rotor of the 1.5mL/2mL centrifuge tube to meet different experimental needs.
Generally speaking, the rotor materials suitable for different speeds are different:
- Low-speed centrifuge rotors below 5000r/min are generally made of ordinary steel, stainless steel and engineering plastics.
- 5000-50000r/min high-speed centrifuges and some super-speed centrifuges, because of their high rotation speed, the greater the centrifugal force generated by high-speed rotation, and the centrifugal force is proportional to the density of the material. Therefore, the rotor materials of high-speed and some ultra-high-speed centrifuges below 50000rpm need to choose high-strength and high-density materials. It is appropriate to comprehensively consider aluminum alloy materials, with light weight, high strength and relatively low cost.
- For ultra-high-speed centrifuges exceeding 50,000 rpm per minute, titanium alloy is better. Titanium alloy has low density, high specific strength and specific fracture toughness, good fatigue strength and crack expansion ability, good low temperature toughness, excellent corrosion resistance, but its price and cost are also relatively high.
Choose the right rotor:
The horizontal rotor is called a horizontal rotor centrifuge because the suspension of the barrel or shelf tube equipped with a centrifuge allows them to swing up to the horizontal plane under the influence of the centrifugal field. Therefore, when the centrifuge is running, the particles are deposited along an unobstructed radial path, away from the rotating center, and evenly deposited at the bottom of the tube or other containers. The flat upper surface of the sedimentation material simplifies the process of removing the supernasant from loosely stacked particles. Through various adapters, test tubes of multiple types or sizes can be centrifuged together, provided that the load is properly balanced.
The fixed-angle rotor fixes the tube at a certain angle to the rotating shaft. Different rotors have different angles, and the common range is 25° to 40°. Although particles are also deposited along the radial path in these rotors, they will soon hit the other side of the tube and slide down from the wall to the bottom. The result is that it can achieve faster settlement than a horizontal rotor with a longer settlement path length. However, because the bottom of the tube is not aligned with the direction of the centrifugal force, the particles are partially collected along the side of the tube. This may make the collection of loosely accumulated particles more difficult than using a horizontal rotor.
Also Read: What is a horizontal centrifuge head
The settlement path of particles:
Among these two types of rotors, various models can provide different capacities and maximum capacity combination RCF. Especially the horizontal rotor, its accessories are suitable for various applications. The bucket hanging on the rotor yoke can carry large containers, such as blood bags or bottles. These buckets can use adapters so that many tubes can be run at the same time for applications such as RIA. The horizontal rotor can also be equipped with a rack or carrier instead of a barrel, which is suitable for rotating RIA tubes or micro test boards.
When it is necessary to quickly granulate small particles, a fixed-angle rotor should be used. Due to its design, the speed of these rotors is higher than that of horizontal rotors. The sedimentation of larger particles, such as cells, protein precipitates, antigen adsorption complexes, urine crystals, etc., can be carried out at a low speed using horizontal rotors. If you use the windproof version, you can use the latter to obtain the maximum centrifugal force. (The windshield improves the aerodynamic performance of the rotor, so as to achieve higher speed.) Regardless of the type of horizontal rotor, the density separation effect of cells is the best.
Laboratory centrifuges are common daily instruments. However, choosing the right centrifuge and rotor system for a specific application can sometimes be a challenge. Understanding the various types of rotors available and their most suitable applications requires a solid understanding of centrifugal requirements. In addition, since the rotor is a major investment in the laboratory, it is also crucial to provide an appropriate level of rotor care and maintenance. This article checks the availability and applications of different types of centrifuge rotors, which are intended to support. Appropriate rotor maintenance procedures are outlined to ensure not only the maximum performance and life of the rotor, but also the safety of laboratory personnel in handling these systems.
In these categories, fixed angle and swing bucket rotors are the most common styles in desktop, low-speed and high-speed floor centrifuge applications. The vertical rotor is mainly used for supercentrifugal. The rotor can be made of a series of materials
