Re: SIM redux

Posted by Peng Xi-2 on
URL: http://confocal-microscopy-list.275.s1.nabble.com/SIM-redux-tp7580938p7580949.html

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Ian is correct -- I shouldn't fully trust the commercial system. Honestly I
am pretty surprised at seeing the hollow, which happens to be similar to
what Michael mentioned... I will redo the experiment and keep you posted.

Peng


On Wed, Sep 11, 2013 at 1:22 AM, Ian Dobbie <[hidden email]>wrote:

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> Peng Xi <[hidden email]> writes:
>
> >      When we use SIM to image the particles, we found surprisingly that
> > even with 200nm out of focus, the reconstructed image shows hollow
> > structure, exactly as what you have seen. The hollow appears to be
> > insensitive to the parameters of reconstruction process.
> >      Based on the image you provided, I guess it may be from the fact
> that
> > your structure is slightly above the focal plane -- you may want to do a
> z
> > series of SIM to verify it.
> >      You can download the original data from:
> > http://bme.pku.edu.cn/~xipeng/FND-SIM.rar     Please pay special
> attention
> > to the last two frames.
>
> This data is pretty horrible to be honest. Scanning through the stack
> there looks to be a squint PSF, or illumination. An orthogonal view
> shows that the XZ PSF is bent. Further doing a FFT on the presented data
> shows that there is no information beyond about 220 nm, so the image
> isn't super resolution at all. I don't think that you can use this data
> to show that a single molecule emitter produces a hollow above or below
> focus.
>
> Ian
>