Rack pipette gun

The invention discloses a rack pipette gun, which comprises a pipette gun shell, a suction nozzle, an adjustment device, a piston rod and a piston. The adjustment device comprises a rack and multiplegroups of gear adjustment mechanisms. The piston rod passes through the rack and is fixed to the piston, two opposite outer sides the rack are both equipped with teeth, each gear adjustment mechanismincludes a gear, a gear shaft, a scale rotary knob and a scale rotary knob shaft, the gear is installed at the middle part of the gear shaft, the gear shaft is equipped with an inner decagonal groove,the scale rotary knob shaft is equipped with an outer decagonal bulge clamped with the inner decagonal groove, a pipette spring sleeved on the piston rod is disposed in the hole of the rack, a limiting ring for limiting the position of the pipette spring is fixed on the piston rod, and the scale rotary knob shaft adjusts the gear so as to drive the rack to move up and down, thereby adjusting thepipetting volume. The invent