Biotek 405 LS, Operator'S Manual

Page: 105 / 240

Cell Wash | 85
The low-flow tubing is used during a wash step when the Flow Rate is set to 1 or
2. It dispenses fluid to the wells slowly enough to avoid damaging the cells. Note
that the low flow line is always open, i.e. some fluid flows through the tubing
during normal dispenses. For this reason, priming the low flow tubing is
recommended for all Prime steps.
Additional Techniques
Delay Aspiration
: Also critical to cell-based assays is delaying aspiration to allow
the slower dispense process to finish before beginning fluid removal from the well.
This option, offered as part of the dispense step, is called
Delay Start of Vacuum
.
Adjust the Aspirate Travel Rate and Aspirate Height
: when defining the aspirate
step select one of the specially designed travel rates that minimize turbulence in
the wells. Increase the aspirate height to leave more residual fluid in the wells to
protect the cell layer. Also, consider using a secondary aspiration as described in
the Cell Wash Strategies described below.
Adjust the Dispense Flow Rate, Height and Position
: when defining the dispense
step be sure to select one of the special Flow Rates that trigger use of the low-flow
tubing, 1 or 2 CW. Also reposition the dispense tubes to aim the fluid at the side of
the wells to further minimize turbulence.
See Cell Wash Strategies below
.
CW+ Dispense Manifold
As a result of BioTek's continuous improvement effort for liquid handlers, the
washer dispense manifold has evolved. The dispense tubes of the improved
manifold ensure fluid hits higher on the walls of the well, minimizing damage to
the cells. "CW+ Dispense Manifold" is engraved on the top of these newer
manifolds to make them easy to recognize. If you do
not have one of these
manifolds you may need to experiment with the
Washer Settings on page 105
(the
CW+ Control
) to improve the performance of your cellular assays. Contact BioTek to
obtain this special cell wash manifold.
Next:
Define a Cell Wash Protocol on page 1
.
Cell Wash Strategies
To give you a starting point for optimizing your own assays, here are some
recommendations for improving your cell wash assays:
BioTek Instruments, Inc.