Abstract: A method for separating a multitude of biological objects by the type of the object. The method utilizes the differences in the viscoelastic properties for the different types of objects. As an example but not limited to: the method can be applied to most tumor cells that might be present in a sample of blood, allowing the tumor cells to be separated from the majority of the normal blood cells.

Abstract: The present invention relates to a method for the separation of biological objects in a solution which have different viscoelastic properties, wherein said method comprises a filtration step allowing the higher viscoelastic biological objects to pass through the membrane while retaining the lower viscoelastic biological objects above the membrane, and a recovery step wherein the separated lower viscoelastic biological objects are recovered above or onto the membrane and/or the separated higher viscoelastic biological objects are recovered in the filtrate. Advantageously, the biological objects are cells. More advantageously, the recovered cells are viable cells. In one preferred embodiment, the cells are tumor cells. In another preferred embodiment, the cells are fetal cells and the method finds an application in prenatal diagnosis.

Abstract: A method for separating a multitude of biological objects by the type of the object. The method utilizes the differences in the viscoelastic properties for the different types of objects. As an example but not limited to: the method can be applied to most tumor cells that might be present in a sample of blood, allowing the tumor cells to be separated from the majority of the normal blood cells.