▎ 摘　　要

NOVELTY - Generating cell-free regions in a cellular aggregate using label-free magnetic manipulation comprises: suspending cells in a paramagnetic culture medium to create a magnetic susceptibility difference, the cells being diamagnetic; seeding the cells and the paramagnetic culture medium into microwells; and placing the microwells over an array of magnet pairs where each magnet pair creates a magnetic field gradient, where the magnetic susceptibility difference and the magnetic field gradient drive the cells towards a spaced region between magnets in the magnet pair having a lowest magnetic field strength to create the cellular aggregate with a cell-free area where the cellular aggregate surrounds the cell free-area. USE - The method is useful for generating cell-free regions in a cellular aggregate using label-free magnetic manipulation (claimed). ADVANTAGE - The method provides a label-free magnetic exclusion technique by which magnetic fields, instead of physical barriers, are employed to create cell-free regions. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: generating particle-free regions in a particle aggregate using label-free magnetic manipulation, where the method comprises suspending particles in a paramagnetic culture medium to create a magnetic susceptibility difference, the particles being diamagnetic, seeding the particles and the paramagnetic culture medium into microwells, and placing the microwells over an array of magnet pairs where each magnet pair creates a magnetic field gradient, where the magnetic susceptibility difference and the magnetic field gradient drive the particles towards a spaced region between magnets in the magnet pair having a lowest magnetic field strength to create the particle aggregate with a particle-free area where the particle aggregate surrounds the particle free-area; a kit comprising a paramagnetic agent, and an array of magnet pairs for applying an external magnetic field gradient to at least one receptacle; and apparatus for generating element-free regions in an element aggregate using label-free magnetic manipulation, where the apparatus comprises: a plurality of microwells that are seeded with elements in a paramagnetic culture medium to create a magnetic susceptibility difference, the elements being diamagnetic, and an array of magnet pairs where each magnet pair creates a magnetic field gradient, where the plurality of microwells with the elements and paramagnetic culture medium are disposed over the array of magnet pairs, and where the magnetic susceptibility difference and the magnetic field gradient drive the elements towards a spaced region between magnets in the magnet pair having a lowest magnetic field strength to create the element aggregate with an element -free area where the element aggregate surrounds the element free-area.