Question: Is it possible to look at a single hormone?

Keith Siew answered on 27 Jun 2013:

It is very difficult to look at a single molecule of a hormone… technically speaking you could view it indirectly using conjugated quantum dots or fluorescent protein tags which will emit light so you can “see” or localise the single molecule (but the latter is often several times larger than the hormone itself and will effect the hormone’s functions, the problem with the quantum dots is that you have to attach them to the protein and that can be a difficult task in the first place!)

To “look” at a hormone and see its structure we typically use a technique called X-ray crystallography… where we take large quantities of the pure hormone and solidify it into a crystal. We then pass beams of tiny wavelengths of x-rays through the sample to “take a picture” of it and work out its shape… (this is how they imaged the structure of DNA).

Another technology available is atomic force microscopy which uses a tiny tiny needle point to “feel” the structure of something by passing it over the object line by line (similar to how a blind person reads brail)… if you had a single molecule of your hormone stuck to something and you pass the needle head over this line by line you could get an idea of its structure in 3D (this has been done with insulin to study its interactions with other molecules).