Decrease in signal and tuning stability
Hi all,
Lately we've been experiencing unexplained signal drops during runs that seem unrelated to antibody or sample integrity. Samples were stained, fixed and run consecutively, but then some acquisition runs see a sharp dropoff in signal after about 10-15minutes. First time it happened we had 1 day of problem-free runs, then the second day saw signal drop offs:
PSI pressure stayed constant, giving no indication of clogs or faulty nebulizer spray. Every sample was washed with H2O just prior to running, the same as the day before where no such issues occurred. When during the final run signal actually rebounded we stopped acquisition and called it quits for the day.
Week after with a different user we saw a similar pattern, after startup and Tuning (with QC values well within spec) sample values noticably dropped after a short time.
First sample was fine, second sample experiences a significant drop in antibody signal and interestingly a widened platinum and EQbead peak. Running full tuning right after again results in a passing QC.
All our users use fresh PFA fixations after antibody staining steps, so release of metal from the cells is unlikely.
Have any other labs seen issues like these where Tuning would pass but proves relatively unstable?
Thanks,
Jan
Lately we've been experiencing unexplained signal drops during runs that seem unrelated to antibody or sample integrity. Samples were stained, fixed and run consecutively, but then some acquisition runs see a sharp dropoff in signal after about 10-15minutes. First time it happened we had 1 day of problem-free runs, then the second day saw signal drop offs:
PSI pressure stayed constant, giving no indication of clogs or faulty nebulizer spray. Every sample was washed with H2O just prior to running, the same as the day before where no such issues occurred. When during the final run signal actually rebounded we stopped acquisition and called it quits for the day.
Week after with a different user we saw a similar pattern, after startup and Tuning (with QC values well within spec) sample values noticably dropped after a short time.
First sample was fine, second sample experiences a significant drop in antibody signal and interestingly a widened platinum and EQbead peak. Running full tuning right after again results in a passing QC.
All our users use fresh PFA fixations after antibody staining steps, so release of metal from the cells is unlikely.
Have any other labs seen issues like these where Tuning would pass but proves relatively unstable?
Thanks,
Jan