Sciencemadness Discussion Board

plant dna extraction - question about image

des68 - 2-3-2010 at 16:52

I extracted a small amount of DNA from lettuce at home. I am trying to identify the strand I see in the image I snapped from my microscope @ 160x. I know I shouldn't see DNA, but then what is this? Thank you for your help!



lettuce dna 10x16 unstained-1.jpg - 96kB

entropy51 - 2-3-2010 at 17:38

Although it is sometimes possible to microscopically visualize a lot of DNA molecules clumped together, I think this is a fiber of something like plant connective tissue, a single strand of cotton fiber, or even a strand of some fabric fiber from clothing or carpet. I would call it an artifact.

There are dyes that will stain DNA, maybe acridine orange, but they might also stain an artifact, depending on what it is.

chemoleo - 2-3-2010 at 17:55

I agree - chromosomes look very different, and you wouldn't see them at this magnification at this resolution. There's no way you'd see DNA (as in free DNA, not packaged in chromosomes) as a double helix (or as a strand) using light microscopy, you'd have to use electron microscopy.

Reduce-Me - 2-3-2010 at 20:03

It looks to me like it's green (can't really tell due to size of the picture).
If it is green, it (likely) contains chlorophyll (and not some other contaminate).
If it contains chlorophyll its likely to be a portion of the plant .
Chances are it's just cells bound together by cellulose.

If you want it (or don't) you can just run it through a coffee filter.

I don't know what you are trying to do, but if you want the DNA for something you can precipitate it out with cold ethanol (after filtering)

R0b0t1 - 2-3-2010 at 21:15

Like said before, it is a strand of something, probably cellulose. Depending on your extraction process, it could be different things, however.

That is quite an odd thing to see. Perhaps it is a chain of those-organelles-that-do-photosynthesis-and-are-really-really-green or perhaps the cells of aforementioned.

[Edited on 3-3-2010 by R0b0t1]