Method for suspending or re-suspending particles in a solution and apparatus adapted thereto

Abstract

A method for suspending or re-suspending magnetically attractable particles is provided. Thereby at least a mixing vessel (10) is provided filled at least partially with a mixture (30) containing magnetically attractable particles (40) at least partially precipitated at the bottom (11) of the mixing vessel (10). An effective magnetic field acting at least in the front end area (3) of the mixing bar (1) is switched on by the magnetic field generating apparatus (4) while the mixing bar (1) is immersed in the mixture (30). Subsequently, the magnetic field is moved away from the bottom (11) of the mixing vessel (10) along with the mixing bar, whereby the movement of the magnetic field along with the mixing bar is carried out such that at least a part of the magnetically attractable particles (40) is raised from the bottom (11) of the mixing vessel (10) and the portion of the particles sticking to the bar is minimized. The magnetic field is switched off in a predefined distance from the bottom which is greater than the distance from the bottom at the time when the magnetic field is switched on. Thereafter, repeated mixing movements of the mixing bar (1) are carried out until the magnetically attractable particles present in the mixture (30) are sufficiently suspended or re-suspended whereby a magnetic field which is switched on does not exist at the front end (3) of the mixing bar (1).

Description

technical field [0001] The present invention relates to a method for suspending particles, especially magnetically attractable particles and beads such as ferromagnetic and / or paramagnetic particles, in a liquid mixture, eg for diagnostic or analytical purposes. Background technique [0002] In the field of sample preparation and sample processing for analytical or diagnostic studies, processes that depend on the utilization of magnetically attractable particles to which specific biological target molecules or contaminants bind are increasingly used. Particles attracted magnetically. Magnetically attractable particles can be separated from the mixture in which they are suspended by an appropriate magnetic field. This applies in particular to automated processing, so that large numbers of samples can be analyzed in a short time without extensive centrifugation steps. This enables large samples to be turned over and allows considerable reduction of the complexity of numerous...

AI Technical Summary

Problems solved by technology

[0007] A problem that arises during the practical application of the methods of the prior art is that particles coated with target molecules, especially biological target molecules or pollutants no longer Sticks to the magnet as particles, but sticks to the magnet as corresponding chunks or flakes

This leads to particles being only poorly suspended and re-sedimented very quickly after they have been released from the magnet, e.g. for washing them or eluting adhering components

This can also lead to poor purge results

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