Multichannel Systems Roboinject Manual - Manual (Page 25)

Roboinject
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Click "Aspirate" tab.
This dialog allows to define the aspiration of compound from the reservoir tubes.
The parameters are the “Velocity” of aspiration in nl/s, the “Surplus Volume” in nl,
and the “Pause after Aspirate” in ms.
“Velocity”: The aspiration velocity for a given compound depends on its viscosity. Samples
with high viscosity should be aspirated slower than samples with low viscosity. This prevents
the accumulation of negative pressure inside of the injection needle leading to the formation
of air bubbles inside of the capillary.
“Surplus Volume”: In order to prevent the injection of minute volumes of mineral oil -
the needle was filled with first - with the last injection, you can define a "Surplus Volume".
The volume will be aspirated additionally to the injection volume, defined in the "Injection" tab.
Values of 50 nl are recommended.
"Pause after Aspirate": You can define a time period during which the injection needle stays
in the compound after aspirating the RNA, DNA or other compounds, before the injector mount
moves upward. This feature minimizes the risk of sucking air into the needle tip. A time span of
2000 ms is recommended.