Elevated baseline above the upper marker on TapeStation traces can indicate overcycling (see FAQ 1.20 above for further details).
A carryover of Purification Beads (PB) results in can also produce a peak around and beyond the upper marker of the TapeStation and also on Bioanalyzer. Make sure not to transfer any beads after the final elution.
A few tips:
Leave approximately 2 µl of the eluate on the beads when removing the eluate for QC and sequencing. i.e., Transfer only 15 – 17 μl of the eluate into a fresh PCR plate or tube. and do not try to transfer the complete sample, as this will lead to bead carryover.
Put your samples once again on the magnet and incubate for 5 minutes.
Transfer 15-17 μl of the supernatant into a fresh PCR plate.
Do not try to transfer the complete sample, as this will lead to bead carryover.
Put your samples once again on the magnet when taking an aliquot to run for QC on Tapestation/Bioanalyzer/Fragment Analyzer, or similar.