- by /u/nintendochemist1I was curious how you all clean the profiles of lenses like tube lens (when smaller) skimmer, etc? Our QQQ is showing charging that my usual cleaning didn’t resolve, so I want to clean the orifices but don’t want to distort their shape. Thanks! submitted by /u/nintendochemist1 [link] [comments]
- by /u/Chemistry_ist_skaryHello MS wizards, I work in a small molecule medicinal lab and we are about to embark on a campaign centers on amidations, mostly with small/simple carboxylic acids. For reaction monitoring, ks the switch to acetic acid from formic acid worth it to improve the ESI- signal of these small acids? If so would it be recommended to have a slightly higher concentration of acid in mobile phase (0.2-0.5% AcOH vs the classic 0.1%? for FA)? submitted by /u/Chemistry_ist_skary [link] [comments]
- by /u/Ok_Investigator5992Looking for help troubleshooting Sciex 4000 QTRAP losing all tune/calibration and loss of all signal in both Q1 and Q3 in positive mode using PPG stds. Negative mode shows signal, but has also fallen out of tune/calibration. I am not worried too much about the tune/calibration, but the flatline in positive mode signal is a problem, and the loss of tune may be an indicator of larger issue… When I directly infuse negative PPGs in negative mode there is good signal; if I switch briefly to positive mode the signal will jump up for a couple cycles, and then flatlines […]
- InstaNovo enables diffusion-powered de novo peptide sequencing in large-scale proteomics experimentsby /u/BioGeekI'm excited to share our newly published paper, "InstaNovo enables diffusion-powered de novo peptide sequencing in large-scale proteomics experiments," now available in Nature Machine Intelligence. In this work, we introduce InstaNovo, a transformer-based neural network designed for de novo peptide sequencing. Trained on 28 million labeled spectra, InstaNovo translates fragment ion peaks from mass spectrometry data into peptide sequences with unprecedented precision, outperforming current state-of-the-art methods on benchmark datasets. Building upon InstaNovo, we developed InstaNovo+, a multinomial diffusion model inspired by human intuition. InstaNovo+ iteratively refines predicted sequences, further enhancing accuracy and reducing false discovery rates. This dual approach combines […]
- by /u/Academic-Company-215So, I just started a new job where we have a waters xevo tq absolute to run antibiotics. I have never worked work a waters instrument before and searching through the waters website is quite irritating, tbh. The colleagues who use the instrument atm had a little workshop with a waters technician on how to operate the system. But none of them is actually familiar with MS or did MS before. So when I ask them any questions they can't really answer them. I'm supposed to be the person responsible for this instrument. What is your maintenance routine in terms […]
- by /u/Front_Ad2774Can I export the peak spot table of Alignment spot view and show the peak Height of the classes? I want to convert Barchart to numeric data. Thank you !!! submitted by /u/Front_Ad2774 [link] [comments]
- by /u/sam_pazosubmitted by /u/sam_pazo [link] [comments]
- by /u/Old-Ordinary18Hello, I am analyzing human serum data for biomarker discovery of a large scale study. I did not conduct the experiments, they were done by a lab tech. The instrument used was Thermo Qexactive. The serum samples were run in 4 batches, each batch has 20 samples. Pooled QCs run with every batch. The first two batches were run in September, the third in November and forth in December. Now, across the batches, I can see an overall RT time drift of 50 seconds. I have manually verified the major peaks and they are the same m/z peaks. The batch […]
- by /u/Josky0Hello, is there a way to install xcalibur on Mac or another way to view mass spectra. RAW on Mac? Thanks submitted by /u/Josky0 [link] [comments]
- by /u/thecrushahHey all, we have a couple complex synthetic peptides where we know we have some trace impurities including some truncations. We wanted to do a full characterization via lcmsms and have already run them on an Exploris 480. I’m having trouble using Thermos software tools like biopharma finder to id the truncations. Do I need to pivot to something like FragPipe to search through the entire list of impurities we have found? Unfortunately we don’t have Proteome Discoverer so a free tool may be best here. I’m mainly interested in n- and c- terminal cleavages, internal truncations, maybe Met oxidation […]
- by /u/pataguccianerHello MS-community, our lab is thinking about substituting our rather old QTRAP 5500 and TTOF5600 (both coupled with Dionex HPLCs) with new instruments As we are already running other Agilent machines, I am thinking about getting Agilent instead of Sciex, especially when thinking about the LC systems as Agilent would also provide LC Systems This would make the interface between LC and MS less prone to errors (I hope!). Furthermore the service would be easier to organize and maybe cheaper. I never worked with Agilent QQQs or QTOFs, are they any good? Do you know how the prices for Agilent […]
- by /u/Cultural_Gur_906I'm a postdoc and soon starting my new lab. I am trying to gather perspectives that might help me decide on the kind of instrumentation to outfit my lab with. The scientific questions I've been asking will require me to do metabolomics and lipidomics, mostly targeted/quantitative. In these experiments, I will also be using stable isotope (such as U-13-glucose) tracers to measure metabolite and lipid turnover in relatively small amounts of mouse tissues. I have solid experience in the metabolite world (though, from stalking this sub, less than a many of you). I have far less experience with lipids, and […]
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