Description

Many applications in clinical and cytological laboratories require rapid processing of the samples under examination. The centrifuges required for such applications should therefore be able to accelerate as fast as possible and to brake at a correspondingly fast rate so that temperature-sensitive samples such as culture cells can be used for further steps of the relevant application without remaining in the centrifuge for a long time. With the development of the Centrifuge models 5702, 5702 R and 5702 RH, Eppendorf offers modern laboratory centrifuges for such applications that have extremely short acceleration and braking times (< 25 sec). Besides speed, another decisive criterion for the quality of a centrifuge in the routine lab is a feature called the re-mixing rate.Therefore, special attention has been paid to the development of a second acceleration and braking ramp that is gentle and yet fast. This function is called a Soft function and enables the user to perform sensitive applications such as density gradient centrifugations to isolate blood cells quickly and reproducibly. The isolation of human mononuclear cells (MNC) from whole blood is one of these standard methods used in cytological laboratories. This cell population, which contains T- and B-lymphocytes and monocytes, can then be used directly for experiments or serves as a starting population for further isolation of single types of cells. To isolate MNC by density gradient centrifugation, the main method used is a method based on the density properties of Ficoll (1). Due to their high density, red blood cells (erythrocytes) pass the Ficoll phase (density: 1.077 g/ml) and form a sediment. A high-polymer sugar, Ficoll also causes agglutination (clumping) of the erythrocytes, thus accelerating sedimentation. Lympohocytes, thrombocytes and monocytes collect at the plasma gradient phase (specific weight less than 1.077 g/ml) and can thus be enriched. The results of the software optimization for the development of an optimum Soft function are summarized below. 4400 max RPM 4x Buckets 100% Adjustable Speed/Time <52 Decibel