position over a consumable stack, the pressure forces liquids within the stack to flow through
the columns or plate wells. The range of selectable pressures is 0.1 to 0.5 psi, in
approximately 0.1 psi increments.
• Creating pressure profiles. A pressure profile consists of a sequence of pressure settings
executed over a user-specified time. For example, you may create a two-minute pressure
profile that starts with pressures at very low values, and then gradually increases these
values over the two-minute duration of the profile. The commensurate effect of such a profile
would be to push liquids through the columns or plate wells very slowly at first, and then
successively increase the flow rate. To suit the specific needs of any particular extraction
protocol, you can create any number of profiles (with a virtually infinite number of pressure
variations) and save them in the software.
• Creating methods, which are sequences of the above steps. For example, a typical method
for a multi-step SPE protocol may look similar to the following:
1. Close manifold.
2. Execute Pressure Profile 1 (pushes liquid through the columns or wells).
3. Open manifold.
4. Pause (waits for you to slide the columns/plate out, add the next protocol liquid, and
then slide the columns/plate back in).
5. Close manifold.
6. Execute Pressure Profile 2.
7. Open manifold.
8. Pause (waits for you to perform another task).
9. Close manifold.
10. Continue sequence of steps in a similar matter until complete protocol is executed.
4.3 Control screens
This section describes the different control screens within the Otto software, along with
associated descriptions of touchscreen selections and their respective functions.
4.3.1 Main screen
Access the main function screens of the Otto SPEcialist from the main screen.
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