1) Operation errors: including 300C hand-held pipette suction; mismatch with suction nozzle, easy to fall off; residual reagent backflow, contamination of piston and sealing ring; rapid suction and drainage, resulting in some liquid remaining on the suction head will affect accuracy.
2) Pipette damage: including scraping the head of the pipette, fracture damage; piston contamination; spring corrosion, etc.
3) The influence of operating conditions: including the unadjusted absorption of liquids with different densities from water; the difference between samples and pipettes is too large.