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Comment by cc439 | Hacker News Reader

" A dose of the venom contains only a few molecules of the neurotoxin, which has a high molecular weight--in fact, the molecules are large enough to be seen under an ordinary microscope."

Does anyone have another source for this, maybe a photo? I spent some time looking around but I can't find anything relevant and it seems a little hard to believe.

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It's wrong, the molecules are many orders of magnitude smaller than is possible to see.

The main black widow venom is alpha-Latrotoxin (http://en.wikipedia.org/wiki/Latrotoxin), which is a 130 kDa protein according to wikipedia. That's large for a protein but there are bigger. Eukaryotic ribosomes are around 2500 kDa, but even they are completely invisible at 20 nm wide, and there are a thousands-millions of them per cell.

It's quite amazing that we manufacture transistors that are as small as a ribosome assembly

Apples and oranges. Protein molecules are far more complex than transistor assembly even if their size are same.

Unless the molecular weight is about 10 pentillion (?) you ain't gonna see diddly! Avogadro's number is a big thing. (6 x 10^23). Now agreed that you don't need a mole of something (especially w/ a high molecular weight) to be able to see it in a microscope. But it's probably at least w/in 4 to 5 orders of magnitude of the right number.

If you mean 10^18, it's a quintillion.

DNA is a molecule, and under the right conditions, you can see it under a microscope as chromosomes.

Only when it is highly condensed. In ordinary conditions you need something like xray crystallography.

Right, only during cell division and you need the right stain.

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