Automated pipetting system

An automated pipetting system for performing programmed pipetting quantitative transfer of fluids between preselected units of an array of test tubes comprising:

• a horizontal table for holding test tube arrays;
• a substantially rigid overhead frame defining a horizontal X-Y pipetting area, which is spaced vertically above said horizontal table for holding the test tube arrays;
• a pair of X-axis guide shafts fixedly mounted and spaced apart in parallel on two opposite sides of said frame;
• a pair of X-axis helical screw shafts rotatably mounted in the frame, each disposed adjacent and parallel to a respective one of said X-axis drive means operatively connected to said pair of X-axis screw shafts for driving said X-axis screw shafts synchronously in rotation;
• a subframe assembly having a pair of X-axis roller sections, each X-axis roller section of said pair having a support wall provided with a helix engagement portion which threadedly engages one of said X-axis helical screw shafts for moving said subframe assembly along an associated X-axis guide shaft in the X-axis directions in response to rotation of the associated X-axis helical screw shaft;
• a pair of Y-axis guide shafts supported on the subframe assembly by being sections connected at its opposite ends to said pair of X-axis roller operatively, said four X-axis shafts being spaced parallel to each other and perpendicular to said pair of Y-axis guide shafts;
• a Y-axis helical screw shaft rotatably mounted in said pair of Y-axis roller sections parallel to the two Y-axis guide shafts;
• Y-axis driving means operatively connected to said Y-axis helical screw shaft for driving said Y-axis screw shaft in rotation;
• a carriage having a pair of Y-axis roller sections rolling on the pair of Y-axis guide shafts, and further having a support wall provided with a helix engagement portion engaging said Y-axis helical screw shaft for moving said carriage in the Y-axis direction in response to rotation of said Y-axis helical screw shaft;
• at least one Z-axis modulator removable unit having at least one row of probes said Z-axis modular unit being removably mounted on said carriage for movement in the Z-axis directions by a Z-axis drive means;
• said Z-axis drive means being operatively connected to each probe for independently driving respective ones of said probes in the Z-axis direction relative to the test tube array on said table, said Z-axis direction being perpendicular to said X and Y axes directions;
• and
• computer control means operatively connected to said X, Y and Z axes drive means.