5.1
Preparation
Selection of flow direction
Linear flow rates and the number of column volumes used during method
development are generally the same as those to be used during the intended full-scale
process.
The recommended flow direction for swellable supports, like Primer Support 5G, is
from top to bottom (downflow). The flow direction is chosen due to the headspace
needed in the first cycles of the synthesis run. For other types of support it might be
different.
The table below lists a few advantages with the respective flow direction.
Flow direction
Upflow
Downflow
•
Can help some supports to spread the
reagents more evenly. Reagents enter the
column through the bottom filter and exit
through the top adapter filter.
•
Using flow direction from bottom to top
also simplifies changing a dirty adapter
filter, since the inlet filter most likely is
dirtier than the outlet filter.
•
Reduces the length of the
tubing connecting the
column. This shortens the
cycle times and reduces the
risk of dilution of the synthesis
reagents entering the column.
Flow rate conversions
The following table shows the unit conversion of flow velocity in cm/hour into flow rate
mL/min for Adjustable Oligo Column.
cm/hour
mL/min
60
28.26
150
70.65
300
141.3
400
188.4
5 Operation
5.1 Preparation
Adjustable Oligo Column Operating Instructions 28967444 AC
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