DESI profiling of 165 proteoforms across over 10,000 single rat brain cells!

 

Wow. Okay, so I was a little (lot) less excited about the desciption of this technology when sea slug neurons were being profiled when the technology was first described here. Those sea slug neurons can be really convenient to work with since they can grow out on a plate to be easily 100x larger than typical cells. However - these are rat brain cells and these are going to be biologically relevant to more than just sea slug biology! 

They start with rapidly murdering the rats and getting to their brains and dissocation of the cells with papain. The cell suspension is then allowed to sink down and adhere to plates (fuzzy on this procedure, but it has been detailed in previous studies). Then those cells are fixed(?) in glycerol and some in ethanol (?) on the slides and they're ready for DESI analysis. 

DESI is like MALDI where you're moving spatially across a slide but the ionization is very different - from a mass spectrometrist standpoint the most important part is that you're multiply charging things. Here they can get the charges up enough that proteins are picking up enough charges to be detected in an Orbitrap (Exploris) running single ion methods.

It's a brief read, and a really interesting one. There is a really cool supplementary video and if you want to find what proteoforms were actually detected you'll want Supplemental Data 5.4. All the files are up on MASSIVE, but I suspect given the unique nature of the data it might be tough to make sense of them with the tools that I have.

Intact protein analysis of 10,000 freaking rat brain cells?!?