Cartridge, electrowetting sample processing system and bead manipulation method

A method for operating a sample processing system (1) and a cartridge (2), wherein the cartridge comprises an internal gap (6) with a bead extraction opening (60), a bead accumulation zone (50) adjacent to the bead extraction opening and at least one hydrophobic surface (17) for enabling an electrowetting induced movement of a microfluidic droplet (23), the disposable cartridge (2) comprising a first part (4) with the bead extraction opening (60) and a second part (3) attached to the first part, such that the internal gap (6) is formed between the first part and the second part, wherein the first part (4) comprises a rigid body and the second part (3) comprises an electrode support element (11′) or a flexible film (3′, 3″),

• the method comprising the steps of:
• inserting and reversibly attaching the disposable cartridge (2) into a cartridge accommodation site (8) of the sample processing system (1);
• providing an electrowetting induced movement of a microfluidic droplet comprising magnetic beads into the bead accumulation zone;
• inserting a bead manipulation magnet (70) into the bead extraction opening (60);
• providing a microfluidic droplet (23) that comprises magnetic beads (52) and moving this microfluidic droplet (23) via the internal gap (6) to the bead accumulation zone by use of electrowetting force;
• exposing the magnetic beads to a magnetic force of the bead manipulation magnet;
• accumulating the magnetic beads in the bead accumulation zone by use of a magnetic force provided by the bead manipulation magnet;
• removing the bead manipulation magnet together with the magnetic beads from the gap via the bead extraction opening;
• and
• removing the disposable cartridge (2) from the cartridge accommodation site (8).

A method for operating a cartridge (2) comprising an internal gap (6) with a bead transfer opening (61), a bead manipulation zone (51) adjacent to the bead transfer opening and at least one hydrophobic surface (17) for enabling an electrowetting induced movement of a microfluidic droplet (23), the disposable cartridge (2) comprising a first part (4) with the bead transfer opening (61) and a second part (3) attached to the first part, such that the internal gap (6) is formed between the first part and the second part,

• wherein the first part (4) comprises a rigid body and the second part (3) comprises an electrode support element (11′) or a flexible film (3′, 3″),
• the method comprising the steps of:
• inserting and reversibly attaching the disposable cartridge (2) into a cartridge accommodation site (8) of a sample processing system (1);
• inserting a bead manipulation magnet (70) with magnetic beads (52) into the bead transfer opening (61);
• providing a microfluidic droplet (23) in the bead manipulation zone (51);
• releasing the magnetic beads (52) into the microfluidic droplet (23) by weakening the magnetic force provided by the bead manipulation magnet (70);
• moving this microfluidic droplet (23) in the internal gap (6) by use of electrowetting force;
• and
• removing the disposable cartridge (2) from the cartridge accommodation site (8).

A method for operating an electrowetting sample processing system (1) and a cartridge (2) which comprises:

• an internal gap (6) with at least one hydrophobic surface (17) for enabling an electrowetting induced movement of a microfluidic droplet (23) comprising magnetic beads (52);
• and
• a bead accumulation zone (50), into which the microfluidic droplet is transferable by electrowetting force and in which the magnetic beads are exposable to a magnetic force of a bead manipulation magnet (70),
• wherein the internal gap (6) comprises a bead extraction opening (60) adjacent to the bead accumulation zone for providing a passage from the gap to an exterior space of the cartridge and for removably receiving the bead manipulation magnet,
• a first part (4) with the bead extraction opening (60) and a second part (3) attached to the first part, such that the internal gap (6) is formed between the first part and the second part,
• wherein the first part (4) comprises a rigid body and the second part (3) comprises an electrode support element (11′) or a flexible film (3′, 3″),
• the electrowetting sample processing system (1) or the disposable cartridge (2) comprising at least one electrode (10) for applying an electrowetting force to the microfluidic droplet (23) and the method comprising the steps of:
• inserting and reversibly attaching the disposable cartridge (2) into a cartridge accommodation site (8) of the sample processing system;
• providing the electrowetting induced movement of the microfluidic droplet comprising magnetic beads into the bead accumulation zone;
• inserting the bead manipulation magnet into the bead extraction opening;
• exposing the magnetic beads to a magnetic force of the bead manipulation magnet;
• extracting the magnetic beads from the microfluidic droplet by removal of the bead manipulation magnet;
• and
• removing the disposable cartridge (2) from the cartridge accommodation site (8).