Pippin Prep users are likely familiar with our “overflow detection” cassette definitions that are found in the “Cassette Type” drop down menu of the Protocol Editor. We use these definitions because Pippin cassettes exhibit a phenomenon
where the elution module liquid volume increases with prolonged sample collections*. To prevent users from inadvertently overflowing the elution modules, we embedded limits in the software to restrict users from programming broad collection ranges.
However, overflowing is remedied by sealing the elution port with tape (which we now provide with our cassettes, or any PCR tape is fine). This keeps the volume constant and prevents the elution module from overflowing. For users using taped elution modules we removed the programming limits, and created the “No Overflow Detection” cassette definition. As the cassette list becomes more extensive, we’re trying to streamline options to make things easier and more uniform for users . Here’s a screenshot of our current list:
For our next software release, we’ll simplify the definitions (see below) such that they all effectively have “No Overflow Detection” – so please be careful. We recommend using tape for all extractions. If you don’t, be careful, or use the “Tight” programming mode.
*Overflowing is due to an electro-osmotic effect caused by the properties of the ultrafiltration membrane in the elution module.