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BloodCellular stratificationCentrifuge tubeDensity gradientgradiente di densitàLaboratory PlasticSangue


Density gradient separation allows stratifying the components of a biological and non-biological sample, in order to isolate and subsequently recover the various stratified components. Stratification remains a problematic operation, as it is necessary to rely on the operator’s ability to stratify the sample on the gradient with great accuracy, otherwise, the mixing of the two liquids of different densities would occur, with the consequent impossibility of stratification. The basic principle of the stratification of two liquids with different densities lies in the fact that the denser liquid must be placed first in the separator tube, and then the less dense liquid must be slowly spread over the first one. 


Technical features

The stratification technique of two liquids with different densities is based on the criteria that the densest liquid is placed first in the centrifuge separator container (Tube), and then the less dense liquid is slowly spread over the first one. The present invention overturns this vision, showing that if the denser liquid is introduced below the less dense liquid, without stratification, the result of the stratification does not change. If a biological liquid is placed in the device and a liquid with a higher density is introduced into the lateral canal (duct) using a syringe, this once pushed into the canal, will exit the center of the bottom of the tube, gradually pushing up the sample to be analyzed. Subsequently, the centrifugation will allow separating the various components. Furthermore, with the syringe supplied, it is possible to recover the various layered components.

Possible Applications

  • Cell biology;
  • Molecular biology;
  • Biochimestry;
  •  Analytical Chimestry;
  • All sectors where gradient separation techniques are used.


  • Simplify the stratification process;
  • reduce preparation time of the sample;
  • reduce contamination risk.