Centrifuges: Guide for selecting equipment
The process of choosing a centrifuge can be complex, as there are many basic variables to consider if you want to make a good choice.
In Ortoalresa, we consider that it is essential to simplify this task, so the user can identify the equipment needed based on not just some variables, but also considering their preferences. To facilitate this work, we have defined this guide for choosing centrifuges, taking into consideration some of the characteristics of the equipment to serve as guides to refine the search based on manners of working.
The basic information needed to start is the following:
1. Characteristics and properties of the tubes to be processed: length, diameter and RCF tolerance
The support of the sample must be able to bear the centrifugal force it will be subjected to. In general, there are materials that due to their properties are more resistant, such as some plastics (polypropylene, polyethylene, Teflon) and other materials that are less resistant, such as glass, which generally does not support RCF values above 4.000 xg.
The size of the tubes is totally decisive for choosing the centrifuge, as it will determine the choice of the equipment you need. The chart on page 22 of our general catalogue provides more information about our tube references.
The versatility of a centrifuge comes from the configuration of its accessories. Each series of equipment has a chart of rotors containing information about the adaptors available for them. In addition, we can enlarge this feature even more by designing multiple adaptors to process tubes with different bottoms with a single set of adaptors.
2. Maximum required speed and max. RCF
A centrifuge operates by applying force to the sample that will produce separation of elements according to density. The different kinds of samples processed and their properties, as well as the different types of results needed by the users makes it indispensable to know this value in order to obtain the desired results.
When choosing equipment, it is necessary to consider the maximum RCF values, or lacking this, the RPM needed for the work.
3. Number of tubes to be processed per cycle
One of the requirements in making the right choice is to know the number of samples to be processed per cycle. This value, combined with the volume of the tube required, will define the size of equipment needed.
4. Type of centrifuge according to temperature control
Temperature is one of the most relevant physical properties in centrifuges, even though not so much attention is given to it generally.
You can read more about Temperature Control on page 26 of our general catalogue titled Temperature control: cooling and heating.
5. Type of rotor required
The type of rotor chosen as well as its maximum speed will affect the type of sample separation. In this type of centrifuges, the most commonly used rotors are angle fixed and swing out.
In an angle fixed rotor, the tube remains in the same position during the entire centrifugation process.
In general, for the same tube volume, they can spin faster than swing out rotors. These rotors produce an oblique separation in the sample with regard to the mouth of the tube. Therefore, they are recommended for processes that require greater RCF or in cycles that require partial extraction of the supernatant.
Swing out rotors move the sample from vertical position up to 90º with regard to the rotation axis. They normally have a greater number of positions per rotor. They are chosen to provide separations that can be directly read from the tube, obtaining pellets and complete extraction of some of the bands.
After this first stage we can refine the search based on:
6. Other technical characteristics
What will really define the equipment you need is the combination of all of them. To facilitate the choice, at pages 30 and 31 of our general catalogue you can compare equipment based on the features considered more important to your processes.
7. Type of equipment control
The type of screen the centrifuge has will define the user’s interaction with the equipment. Our centrifuges have three types of controls: LED, LCD and TFT, all of them display messages on routine operation as well as warnings regarding the operation and status of the equipment.
These screens can also be used to customize certain actions such as the opening of the lid at the end of the process, time to start, etc.
For more information on this, click here.
Equipment Configurator
After evaluating the needs of our customers, we have concluded that action must be taken, and with the aim of facilitating this selection process, we developed a tool to facilitate the process of searching and selecting the most suitable centrifuge for the needs of each of our customers.
Our configurator presents six steps, which must be followed through the selection of a series of parameters. Each step contains a brief introduction that explains the importance of the value of the selection as well as with a short description of the available options.
Try out our configurator!