Monday, May 4, 2015
Direct Infusion SIM for rapid and accurate quantification!
Umm...so..this is the first Google Image that comes back for "direct infusion needle". We're gonna run with it. I've got a lot to do today, but this was too cool not to share.
The paper in question is in this month's Open Proteomics and its from Christina Looße et al., you can find it here. (In case you were wondering why the color change...I don't know what that "B" thing is or how to convince my keyboard to make it...yes, I'm that dumb...)
In this paper they got a synthetic peptide to optimize with and then went to quantify this peptide in a complex digest. They used all the normal techniques, like SRM and SIM (connected to an LC), then they did the title experiment. Direct infusion (with nano emitters and with the HESI source). Turns out that you can quantify just as well without an HPLC! Obviously the background is going to be more complex and the sensitivity will be lower since you have all your compounds at once, but I'll be darned if it doesn't work.
Best of all? They were getting CVs with the synthetic peptides hitting <15%. Not too shabby, right? So, if you're in a hurry or your LC is going through standard maintenance you can still quantify peptides quickly and accurately on your Q Exactive!