Wed Mar 12, 2014 3:30 pm by mleipold
Hi Rob,
Based on my records, the HIMC has received at least 3 different 4-element bead lots in the time frame 9/19/13-3/5/14. The last two bottles (2/19/14 and 3/5/14) have been from the same lot, so maybe DVS has scaled up.
Regarding Tb and Tm: in my experience, it can be a bit arbitrary which is the highest intensity signal (note: I'm talking about pulses-count mode, since we're still using that version of software). Generally speaking, between cleanings, one of them is consistently on top. However, after cleanings (and XY realignment, etc), occasionally it will switch. In most cases, if you run tuning solution for a super-long time, the two will eventually wind up overlapping (they're at the same concentration, and have close to the same "brightness", at least for CyTOFv1). For the purposes of calculating the <3% ratio, it doesn't matter which one is on top.
Based on observation, I think that Tb has a slightly higher affinity for the plastic tubing and such than Tm does. This is why at first (or on the first injection of tuning solution), Tm can be on top and then with more injections/runtime, they start to merge as the system equilibrates (stops artificially depleting the Tb). Similarly, when you then use Wash solution to remove residual Tuning solution, the Tb signal stays higher for longer.
Mike