Talk:Filter binding assay

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Although I'm biochemist, I'm not really used to binding assays (basically it hasn't much to do with my research topic) and therefore I don't want to modify directly the article. However, I think the image (Agonsits.png) showing the difference between two different dissociation constants is not totally correct. In my opinion, the lower affinity profile (green one) should start at 0 nM and progress with a lower slope until reach the maximum binding at a higher concentration than the red one (crossing, of course, the abscissa of 50% binding at a higher concentration than red Kd). The difference between a higher affinity profile and lower one should be the shape of the plot, whereas now both curves have exactly the same shape but with different starting points.

If the creator of this article agrees with me, I can modify myself the image, but as I said I prefer not to do it without having his or her opinion.

Doubts regarding binding to nitrocellulose

I have some doubts regarding this paragraph:

"A filter binding assay is a simple way to quickly study many samples. It measures affinities between two molecules (often protein and DNA) using a filter. The filter is constructed of nitrocellulose paper, which is negatively charged. Since most proteins have a net positive charge, nitrocellulose paper is ideal for immobilizing proteins. DNA is negatively charged due to the phosphate backbone and will not "stick" to the nitrocellulose on its own, however, any DNA that has been bound by protein will stick."

In Northern and Southern Blotting DNA and RNA, respectively, are blotted to a nitrocellulose membrane, so it seems that both nucleic acids "stick" reasonably well to this membrane. Moreover, the structure of nitrocellulose suggests the charge of the membrane to be neutral, because the nitrogen harbours a positive charge and the oxygen a negative one. In any case I preferred not to change the page because I am not sure if I am correct on this.

— Preceding unsigned comment added by Esskeen (talk • contribs) 23:04, 29 December 2014 (UTC)

I share the same doubts ~2026-27983-82 (talk) 22:09, 8 May 2026 (UTC)