Why is the centrifuge tube called the ep tube?

Why is the centrifuge tube called the ep tube?

Origin of the name

In 1963, the world’s first eppendorf microcentrifuge tube was born in the German eppendorf company, providing a new tool for molecular biology micromanipulation experiments. Today eppendorf (ep tube) has become a special name for the indispensable small tube in the laboratory.

Size classification

According to its size, it is divided into 1.5ml, 2ml, 5ml, 10ml, 15ml, 50ml, etc. If your centrifuge is equipped with 30ml or other specifications of centrifuge tubes, you should consider importing them. In addition, the centrifuge tube has a round bottom and a conical bottom, as well as a screw cap and a plug cap. The screw cap centrifuge tube has a fine scale, and the plug cap has only an overall capacity indicator.

Material classification

Centrifuge tubes commonly used in laboratories are plastic and glass. Generally, plastics are used more, because glass centrifuge tubes cannot be used in high-speed or ultra-speed centrifuges. Plastic centrifuge tubes are made of PP (polypropylene), PC (polycarbonate), PE (polyethylene) and other materials. The performance of PP pipe is relatively good. The plastic centrifuge tube is transparent or translucent, and you can visually see the centrifugation of the sample, but it is relatively easy to deform and has poor resistance to organic solvents, so it has a short service life. Therefore, laboratories generally buy centrifuge tubes frequently. The various materials are introduced separately below.

PP (Polypropylene): translucent, with good chemical and temperature stability, but it will become brittle at low temperatures, so don’t centrifuge it below 4°C.

PC (polycarbonate): good transparency, high hardness, high temperature sterilization, but not resistant to strong acids and alkalis and some organic solvents such as alcohol. Mainly used for ultra-high speed centrifugation above 50,000 rpm.

PE (polyethylene): opaque. It does not react with acetone, acetic acid, hydrochloric acid, etc., and is relatively stable, and tends to become soft at high temperatures.

PA (Polyamide): This material is a polymer of PP and PE material, translucent, chemically very stable, and not resistant to high temperatures.

PS (Polystyrene): Transparent, high hardness, stable to most aqueous solutions, but will be corroded by a variety of organic substances. It is mostly used for low-speed centrifugation and is generally for one-time use.

PF (polyfluoride): translucent, can be used at low temperature, if it is an experimental environment at -100℃-140℃, centrifuge tubes of this material can be used.

CAB (cellulose butyl acetate): transparent, can be used for the gradient determination of dilute acids, alkalis, salts, alcohol and sucrose.

Selection of centrifugal tube

Chemical tolerance

There are many factors that affect the chemical resistance of laboratory equipment, so the true chemical resistance also depends on the actual test conditions. Compounds can affect the strength, elasticity, surface properties, color, appearance and weight of plastic products. The basic patterns that cause these changes are as follows:

(1) The compound destroys the polymer chain, leading to the loss of physical properties, including oxidation; the reaction between the chain and the functional groups on the chain; depolymerization.

(2) Physical changes, including softening and swelling of plastics caused by solvent absorption; solvent penetration through plastics; decomposition in solvents.

(3) Stress cracking caused by internal and external stress generated by the “stress cracking agent” reaction.

When loading reagents in centrifuge tubes, it is necessary to consider the relative influence of centrifuge tubes on PP and HDPE. Centrifugal force

The centrifuge separates samples by centrifugal force, and acceleration and speed are very important parameters. The acceleration is set relative to the gravitational acceleration g (9.81 m/s2) on the earth’s surface. The centrifugal effect is mainly measured by the relative centrifugal force (rcf). Compared with the rotation speed per minute (rpm), the relative centrifugal force is more accurate.

Centrifuge adaption

Good matching can ensure the integrity of the centrifuge tube during use, and will not be deformed or damaged.

As a centrifuge tube manufacturer & supplier of medical equipment and equipment, Huida can not only provide customers with overall solutions for laboratory equipment, but also provide a full range of high-quality products and related services for laboratory plasticwares. Welcome to send an inquiry for more details.