Not sure if I understand your question. But to expand further they are doing (one way) of particle sizing on the purified protein only, not the jab formulation. With electron microscopy, you cannot image particles in a solution, they have to be separated from the medium. This excerpt is describing the procedure where they take a gold grid, coat it with graphene oxide in order for the proteins to stick to the grid better, then flash freeze it with liquid ethane. For these samples they collected 1.1 million particles in about 2 micrograms of protein
The freezing is required to "lock-in" the particle shape (aka morphology) as it appears in solution because if it dries it would collapse. Once that's prepared its in a form you can actually image with the EM then use image analysis software to pick out all the particles from (usually) thousands of images. They have size and shape filters applied to only get the particles they want (and exclude particles they dont). Each pixel in the image for this analysis was 0.087nm, particles were ~0.35nm, so your looking at only 3-4 pixels wide per particle.
If you want to see what the images look like search "Cryo em protein micrograph"
This instrumentation is crazy expensive, your talking $5-10 million for the instrument alone, 500K for the service contract, consumables, analysts, and another couple million to build the facility to house it. Not a run every sample type of thing but good for exploratory work.
Why prep if it is not going to be done? Make me wonder, but you could be right.
Not sure if I understand your question. But to expand further they are doing (one way) of particle sizing on the purified protein only, not the jab formulation. With electron microscopy, you cannot image particles in a solution, they have to be separated from the medium. This excerpt is describing the procedure where they take a gold grid, coat it with graphene oxide in order for the proteins to stick to the grid better, then flash freeze it with liquid ethane. For these samples they collected 1.1 million particles in about 2 micrograms of protein
The freezing is required to "lock-in" the particle shape (aka morphology) as it appears in solution because if it dries it would collapse. Once that's prepared its in a form you can actually image with the EM then use image analysis software to pick out all the particles from (usually) thousands of images. They have size and shape filters applied to only get the particles they want (and exclude particles they dont). Each pixel in the image for this analysis was 0.087nm, particles were ~0.35nm, so your looking at only 3-4 pixels wide per particle.
If you want to see what the images look like search "Cryo em protein micrograph"
This instrumentation is crazy expensive, your talking $5-10 million for the instrument alone, 500K for the service contract, consumables, analysts, and another couple million to build the facility to house it. Not a run every sample type of thing but good for exploratory work.
I understand what you are saying now. It was just the prep work. Thanks.