Patent ID: 7546855

Claim:
A method for sealing of a reaction vessel having an access opening, such that the vessel is repeatedly accessed by a fluid transfer mechanism, and subsequently self-sealed, comprising: sealing said access opening with a cap having an access port, wherein said cap has an internal surface which faces the reaction vessel, and an external surface, which faces away from the reaction vessel, wherein said cap internal surface is tapered from said access port outward toward the reaction vessel; seating a dipolar magnetic ball in said access port, wherein said ball is sized to fit over said access port, such that a portion of said ball seats partially in said access port, sealing said access port; mounting a ring magnet which produces a magnetic field to said cap external surface wherein said ring magnet is spaced from said cap such that the magnetic field is sufficient to hold said dipolar magnetic ball in said access port, and to reseat said dipolar magnetic ball in said access port after said reaction vessel is accessed; transferring a fluid into the reaction vessel wherein the fluid transfer mechanism pushes the ball down into the reaction vessel until it rolls out of the way of the fluid transfer mechanism, and wherein the fluid is transferred into the reaction vessel while the fluid transfer mechanism is in the reaction vessel with the ball being pushed out of the way of the fluid transfer mechanism; and withdrawing the fluid transfer mechanism from the reaction vessel and allowing the ball to reseat in the access port seal of the reaction vessel.