Understanding Flowthrough, Wash and Eluate Fractions

[indoubt]

chromatography:

we have to collect the fractions from the column. i wonder what is the difference between;

flowthrough fraction, wash fraction and eluate fraction?

i think i know what it means with eluate fraction, but what about the other two?

hope for replies!
thanks a bunch!

 

[Moonbear]

It seems there are a few folks posting here working on similar topics in class (i.e., chromatography). Why don't you try to help each other out a bit? You'll learn it better to try answering each other's questions (it's like practicing for a quiz or test).

Please start out by telling us what you think the eluate fraction is, since that's the one you know.

 

[PRodQuanta]

I'm not sure quite what you mean, but I know chromatography has to do with the substances in a mixture's affinity to the paper. I hope this helps you out a little.

Paden Roder

 

[Monique]

indoubt, just think about the different steps you go through during chromotography when you apply your sample to the column. You apply your sample, you wash it, you elute it. Washing takes away non-binding or low-affinity binding molecules, eluting is a wash step where the high-affinity molecules binding to the column will lower their affinity and wash out.

 

[Moonbear]

I'm not sure quite what you mean, but I know chromatography has to do with the substances in a mixture's affinity to the paper. I hope this helps you out a little.

Paden Roder

You're thinking of thin layer chromatography (TLC). Indoubt is asking about column chromatography. The basic principles are similar in terms of adsorption of a compound to a matrix, but column chromatography takes it a further, allowing you to not only separate your sample, but collect it in a more purified form so you can then use it for something else.

Here's a website with some basic column chromatography methods and pictures of the procedure. At the end, it demonstrates using TLC to confirm successful separation of the components of the original mixture. http://www.wfu.edu/academics/chemistry/courses/CC/