Rainin Pipetman F Series Manual

Contents

Rainin Pipetman F Series Manual Manual pdf 7 page image

5If you need to dedicate Pipetman-F for a particular solu-tion only (oft-repeated tests), you may wish to retain thesetting semi-permanently. Simply record the setting anda solution or test code on the supplied label and place itin the indentation at the top of the handle. Then you cantell at a glance that this pipette has been calibrated todispense the desired volume of a particular solution.Pre-Rinsing RecommendedWhen pipetting some solutions (especially serum, pro-tein-containing solutions, and organic solvents) a signif-icant film may be retained on the inside of the wall of thetip, resulting in an error that may be larger than the tol-erance specified. Since this film remains relatively con-stant in successive pipettings with the same tip, excellentprecision may be obtained by refilling the tip a secondtime and using this volume as the sample. Successivesamples from this same tip will exhibit good repro-ducibility (low variance).This procedure is recommended when critical repro-ducibility is required. In short, intertip and intratip vari-ances will be minimized if pre-rinsing is practiced.Reverse Mode PipettingAnother method for reducing error due to film retention isreverse mode pipetting, where the sequence of op-erations in the pipetting process is reversed, as follows:1. Mount a disposable tip on the pipette shaft.2. Depress the pushbutton fully to the SECOND STOP.3. Immerse the tip in liquid and return the pushbuttonslowly to the full UP position. Pause a moment (morewith viscous liquids) for the liquid column to reachequilibrium in the tip.4. Wipe any excess liquid from the outside of the tip with-out touching the orifice.5. To dispense, rest the end of the tip against the receiv-ing vessel wall and press the plunger to the FIRST STOP.Hold this position a few seconds, or long enough forthe liquid column to reach equilibrium again.6. Remove the tip from the receiving vessel without blow-ing out the remaining liquid.7. Return the excess sample in the tip to the original sam-ple container, if desired. Discard the used tip.