A high-throughput magnetic separation method for circulating tumor cells

Abstract

The invention discloses a high-throughput magnetic sorting method for circulating tumor cells. The method comprises the following steps of: sample purification, namely mixing whole blood samples withmagnetic beads for incubation, binding the magnetic beads and target cells in the whole blood samples, and removing cells which are smaller than a sorting critical radius from the whole blood samplesincubated through the magnetic beads through a purification structure region of a microfluidic chip; cell focusing, namely carrying out cell focusing on the samples purified in the step (1), focusingthe cells which are greater than the sorting critical radius at a central position of the chip and still keeping the cells which are smaller than the sorting critical radius in an original path; and magnetic sorting, namely carrying out magnetic bead sorting on the samples subjected to cell focusing in the step (2), distributing magnetic bead-bound cells into a magnetic bead cell collection port to be collected under the attraction of a magnetic frame, and enabling non-magnetic bead-bound cells to flow into a non-magnetic bead cell collection port in a straight line and to flow out of the non-magnetic bead cell collection port to be collected. By using the high-throughput magnetic sorting method, the background cell clearance rate is high, the tumor cell capture rate is high, the tumor cell survival rate is high, and high-throughput capture can be achieved.

Description

technical field [0001] The invention relates to a method for sorting circulating tumor cells, in particular to a method for sorting circulating tumor cells using a microfluidic chip for high-throughput magnetic sorting of circulating tumor cells. Background technique [0002] Tumor is a major disease that endangers human health in today's society. At present, the most effective way to treat tumors is surgical resection. However, even after surgical resection, patients still have a certain probability of tumor recurrence and metastasis. One of the reasons for the poor prognosis is cancer. Cells can easily enter and travel through the blood. Such free tumor cells may already be present in the blood of these patients prior to surgical resection. [0003] In 1896, Australian scholar Ashworth found cells similar to tumor cells in the peripheral blood of a patient who died of cancer, and thus proposed the concept of circulating tumor cells (CTC). CTC refers to some cancer cells ...

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Problems solved by technology

However, the inventor also found that there are many problems in the sorting equipment and method during the experimental research.

First of all, the main function of the microfluidic chip is to remove background cells. The samples passing through the microfluidic chip still need to rely on the existing commercial magnetic sorting equipment for CTC sorting, which makes the whole system too large in size. The cost is high, and the transfer pipeline is cumbersome; secondly, the structure of the existing mature magnetic bead cell sorting equipment is mostly a magnetic column-like structure. In the experiment, the sorting of this structure is limited by the flow rate, and it is impossible to pass a large amount of liquid in a short time.

Third, during the sorting process, because all cells are magnetically sorted in a disordered state, the sorting efficiency is poor, and some cells will remain in the magnetic column, resulting in the loss of CTCs; fourth, although this method is harmful to white blood cells, The average clearance rate of red blood cells and platelets is relatively high, but the remaining background cells are still too large relative to the number of CTCs, and the extraction purity still needs to be improved

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