Electron dense and electron-lucent

[Asmaa Mohammad]

Hello,

Chromatin in the living cell is divided into Heterochromatin and Euchromatin. My book states that the Heterochromatin, when examined by the electronic microscope, is electron dense, and the Euchromatin is electron-lucent.

I don't understand any of the concepts in bold.

And I would appreciate a simple explanation for both of them.

Thanks in advance!

 

[BillTre]

These term relate to how the materials react in an electron microscope.
Electron Dense means something that interacts more strongly with electrons in a transmission EM and therefore looks darker.
Electron-lucent would presumably be the opposite.

In traditional transmission electron microscopy, electron density can be (and often is) increased by staining/reacting biological materials with heavy elements like uranium or osmium. The sample then interacts more strongly with the electron beam of the EM, thereby improving contrast.

 

[SciencewithDrJ]

https://en.oxforddictionaries.com/definition/us/electron-dense