My goal in this project was to compare the morphology of leg muscle fibers in healthy mice vs. MACF1 mutant mice using transmission electron microscopy (TEM).
As members of New York University’s Microscopy Lab, Alice Liang, the director, Chris Petzold, the lab manager, and myself worked in tandem to design, process, section, and image these samples. We followed a standard TEM processing protocol to preserve the tissue before embedding it in resin. Once polymerized, the blocks were sectioned onto TEM grids and stained with uranyl acetate (UA) and lead citrate. This process can take from 2-3 weeks to complete depending on the workload of the core.
Imaging was done on a Philips CM12 TEM with Gatan camera.
We collaborated with Julien Oury and his PI Steve Burden to ensure the TEM images captured representative regions of interest from both healthy and mutant mice.
We focused specifically on longitudinal muscle fibers displaying mitochondria and t-tubules and found a visible difference between the morphology and organization of these particular organelles in the different mouse groups. Once all parties were in agreement about the results, we chose one of the best, most representative TEM images from the healthy mouse to color and submit for the journal cover.
I used Adobe Photoshop to highlight different components of the muscle fibers (red and orange) as well as the mitochondria and t-tubules (purple).
For me, imaging wasn’t the hard part of this project—instead, it was choosing which image to color out of the dozens of beautiful ones we collected. Finding which color combinations work together is the next hurdle. I tried various combinations before settling on this one, and I’m happy with the results.
I think muscle tissue is one of the most visually pleasing tissues to image with TEM. The patterns are almost hypnotizing.
Thank you, Kristen Dancel-Manning, a graphic designer turned electron microscopy specialist, and now science illustrator and visual communicator.
Author: Kristen Dancel-Manning, BFA, MS
Microscope: Philips CM12 TEM with Gatan 4k camera
Specimen: mouse muscle fibers
Core Facility: NYU Medical Center’s Microscopy Lab