Tuesday, June 4, 2024

Set your Q Exactives up for optimal TMT32/35-plex (90k res?) cycle times!

This week at ASMS there were some reagents on the big stages, including what appears to be either a TMT32-plex or TMT35-plex commercial release. 

While I haven't had time around packing the lab to really dig into the fine details, it appears that a minimum of 90,000 resolution @ m/z of 200 is required to achieve baseline separation of all the tags. 

If you're running on Q Exactives you probably noticed that you do not have a 90,000 resolution setting. On a Classic or Plus you've got 70,000 and 140,000. While you could just run at 140,000 that's a wopping 512 milliseconds per MS/MS scan! 

Running at 90,000 would only be 329 milliseconds, which is an extra MS/MS scan/second. Which would definitely add up across a run. 

Assuming you've got the setup I put up there (70k MS1 and 90k MS2) a top 6 would be 2.2 seconds, rather than 3.6 seconds. 

That's 3,200 MS/MS in 120 min vs 2,000 MS/MS in 120 min.

No, that's not a lot of spectra, but you're 32-plexing! You're offline fractionating and stuff, right? Plus it's TMT, you literally do not care about your chromatographic peak shape.

Also, in one of the slides it looks like they show not quite baseline resolved spectra at a lower resolution which would obviously be faster. 

(Oh yeah, and an HF or HF-X would be about 2x the number of spectra)

How to do this? 

MAXQUANT.LIVE.LIVE.LIVE.LIVE.LIVE (sing it with me, people who plan to retire with a Q Exactive still in their possession!) 

MAXQUANT.LIVE 2.1 is now valid until January 2026!!

If you haven't ever used MaxQuant.Live, I made instrument triggering methods you can download here for the Q Exactive HF(it works the same for Q Exactive Classic, I've never tried Plus) as well as a powerpoint that walks you through the steps. You go into the beta and there are two little paperclips to download the .meth file and the .pptx. 

No comments:

Post a Comment