Link to this post | posted 05 Dec, 2020 19:03
mdgainey	Hi all, has anyone used an SEM with a TEM detector to image their phages? We are hopefully going to be getting a new SEM with a TEM detector for our new science building next year, and I am hoping to use it to image our phages in house for the first time. We are still deciding on the specs to purchase, so any specific information would be helpful. Edited 05 Dec, 2020 19:04

Link to this post | posted 10 Dec, 2020 16:45

cdshaffer

Our dept purchased an SEM with a TEM detector a couple of years ago. We tried several times but were never able to get sufficient resolution to see phage on the grid. To be fair, we were just testing older grids that had been returned after imaging at the EM core so fresh grids might have given us viable images; but it really looked like we were never going to get the resolution we needed to see things as small as phage. If you can get it to work please post your protocols we would be very interested, it would open up some interesting curriculum opportunities. Sorry I don't know any of the specifics on our system but I could ask our microscope facility if you want the specifics. Edited 10 Dec, 2020 16:49

Link to this post | posted 10 Dec, 2020 18:14
mdgainey	Thanks Chris, they are going to test out some samples before we purchase one, and if I can get it to work well, I would be happy to share protocols.

Link to this post | posted 10 Dec, 2020 18:23
viknesh	Hi Maria We have imaged phage using the TEM mode on an SEM. The quality and magnification are understandably lower. I've attached one of the better micrographs, and you can see that a lot of the usual detail we can visualize with TEM is lost. 1.64Mb

Link to this post | posted 10 Dec, 2020 18:58
cdshaffer	Ok, those look pretty good. I now suspect our issue might have been with the age/storage of the grids. Thanks

Link to this post | posted 21 Jun, 2023 17:54

mdgainey

We did end up sending identically stained grids (Cluster M3 bacteriophage Nanosmite) to 3 companies that sell SEM's with STEM detectors Thermo-Fisher, JEOL and Zeiss and they each generated images of them as a part of their demo for us. We got the best results with Zeiss, but also some nice results with the Thermo-Fisher set up. I will attach these images (just keep flipping through until you see the phage samples. The SEA team can chime in here bc I am not an EM expert, but I thought at first blush the images that they obtained look good enough to meet the programatic standards, but I don't think that they will be as good as some of the TEM images that I have seen… We ended up going with the Thermo-Fisher model with a STEM3+ detector cat # 1091077 (detector is ~$27k) just simply due to cost differences. It took a long time to get them to come out and set it up for us (not happy with their service=( but I just recently had the chance to try it out with the same samples (now 2.5 years old). I have attached my first image, which is not as good as their demo images possibly due to sample age, our set up, or the fact that I don't really have any microscopy skills. As I get more comfortable I will post some additional images that I obtain so folks can get a sense of what this STEM setup can do. 3.22Mb

Link to this post | posted 21 Jun, 2023 18:06
mdgainey	Here are some screen shots of the demo in power point. I could not attach the demo files. 1.53Mb

Link to this post | posted 21 Jun, 2023 18:36
debbie	Maria, Thanks for sharing this. i hope others find it helpful. best, debbie