Analytik Jena CyBio Well vario OL3381-25-300, Operating Manual

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102 Release: 2017 CyBio
®
Well vario
Operation
direction reversal, an additional volume (D1) is dispensed. Due to piston reversal, this
volume is smaller than the aspirated additional stroke volume (A2). The tip retains the
nominal pipetting volume (D2) and a residual volume (D3).
Exact volumes can be dispensed in the next step (4) (in a single step or a multi-step se-
quence). After the nominal pipetting volume has been dispensed, the pipetting tip will
contain the residual volume (D3) that results from upper direction reversal. This volume
is dispensed with additional stroke (5) into a waste box or the reservoir. Since the stroke
length is greater than actually required for the residual volume (D3), the residual vol-
ume is completely dispensed. Finally, the amount of air is dispensed (D4). A volume cy-
cle is completed by "Motion into zero-position".
A "Move pistons into zero-position" command (6) triggers upward piston motion to
their initial positions, thus excluding the lower freeplay.
This process must be triggered with no liquid present, i.e. the lifter must be in such a
position that the tips cannot make contact with liquid. Liquid which is aspirated in the
process may result in dosing errors or contamination of pistons.
7.4.2 Aspiration Without Additional Stroke
Fig. 114: Aspiration without additional stroke
Where liquid is aspirated without an additional stroke, it must be dispensed in a single
step, in order to achieve precise results. This cycle must provide for a motion length that
is greater for dispensing (4) than that for aspiration (2). Since the reversal point of pis-
ton motion lies within the motion range that is covered by the pistons for dispensing,
1 Zero-position
2 Aspiration
3 Upper freeplay
4 Dispense with additional stroke
5 Move to zero-position
A1=D1: nominal pipetting volume
D2: air