These are protein crystals under a microscope! Proteins can be very tricky to crystallize. This is because they are large molecules whose electrostatic interactions can cause difficulties when trying to form the very ordered structure that crystals possess. Sometimes it can take weeks or months to form crystals, but sometimes it happens very quickly!
The process of crystallizing protein is an art form. I am not a Da Vinci so to speak and won’t go into too much detail about how it’s done - but if you’re interested, I suggest looking up “hanging / suspended drop diffusion,” a popular method of making xtals.
Why are protein crystals useful? Because of their intrinsically ordered structure! This allows us to make atomic maps and models of them down to Angstrom levels of precision using X-ray crystallography.
When X-rays are shined on the crystal, it produces a “disco ball” like diffraction pattern, unique to every crystal, that can be translated into a spatial map of the location of every atom in the proteins making up the crystal.
It doesn’t stop there! You can use this technique for small molecules, like drugs, as well.
Crystallography has seen a large paradigm switch as cryo-electron microscopy has demonstrated similar resolution in protein structure, and it may start to predominate the field of structural biology within a short period of time. Cryo-EM is a story for another post.
By the way, these are green fluorescent protein (GFP) crystals! ——————————————- #biology #biochemistry #protein #xray #crystal #science #structuralbiology #microscopy #microscope #pretty