6,500 proteins per (LARGE) mouse cell (oocyte) and studying age related changes!

 

I wasn't sure if I liked this study or not, but then I got to an interesting and very counter-intuitive observation and then the biology and decided that I did. 

It's not the first single cell oocyte paper we've seen, and it should be noted that they are quite big cells. These authors estimated them at about 2 nanograms of protein, which seems right based on what I remember from another study. 

One thing that I find really surprising here is that - unlike previous studies - this group tried the reduced volume of 384 well plates and found autosampler vials more reproducible. I'm stumped on this one. This is contrary to everything I've seen and Matzinger et al., found and is frankly just counter intuitive across the board. 

The surface area of an autosampler vial is huge, comparatively to the bottom of a 384 well plate. I do find it a complete pain in the neck to calibrate some autosamplers for accurately picking up out of 384 well plates, but I don't know how much that plays in here. Also some glass binds less peptides than some plastics. Insert shrug. 

That aside, the authors put one oocyte into things with the CellenOne and then add digest. Incubate and inject. 60 min run to run on a 50um x 20cm column and running diaPASEF with a 166ms ramp time. 

Data analysis was in SpectroNaut. 

Okay, and the reason this is escaping the drafts folder is because the biology is really cool. They look at both artificial (handling) and natural (aging linked) conditions and how they effect single oocytes. There are a lot of people out there who care about how those things (probably not in mice, but maybe?) change throughout the aging process!