Re: Radio opaque biomolecule?

Oh, real-time imaging sure. But "radio opaque" isn't the same thing as
"precisely detectable".

For example, there's luminescence or fluorescence to consider as
alternatives, or merely pigmentation.

I used to work in a lab that used a (stupidly, criminally expensive)
CCD-coupled camera in a darkroom to image bioluminescence in mice
through whole-body imaging. Essentially they'd inject luciferin (which
apparently isn't toxic), knock the mice out with anaesthetics, and then
image them for 30s+. You'd clearly see the areas that were expressing
luciferase using this method.

Alternatively, there are other systems (also requiring anaesthetics for
animals you can't train/ask to sit perfectly still) that use confocal
lasers to excite fluorescent molecules and image them by scanning at
variable resolution. The laser allows deep penetration of
excitement-frequency light, but you still need to be able to see any
emissions. If, even after saturating your fluorescent molecules, there
simply isn't enough light to see a few photons escape the body and hit
the camera, then you're out of luck.

On 02/01/12 17:26, Veera wrote:
> hmmm i'll dig in to it. so far people have been successful in imaging
> realtime gene expression in single living cells.
>
> On Jan 2, 10:11 pm, Cathal Garvey <cathalgar...@gmail.com> wrote:
>> As pointed out by Jelmer, there probably isn't much in the "radio" area
>> of the spectrum, but if you meant more generally "Are there any
>> molecules that block useful scanning frequencies", then yes, there are.
>> I believe (i.e. am not certain) that melanin can block X-rays to some
>> extent, so a tight clot of melanin might be slightly X-ray opaque.
>> Calcified matter is X-ray opaque, as is fibrosis, so it's probable that
>> any knot of tightly woven protein would be somewhat opaque also.
>>
>> That's all structural stuff, of course. But structure's where it's at;
>> for some frequencies, you'll need larger obstructions to absorb the
>> light effectively. For radio, you'd need conductive bones or something;
>> ask a radio tech for the specifics on absorption of radio and translate
>> that into a biotech context. It wouldn't be easy, certainly.
>>
>> On 02/01/12 06:40, Veera wrote:
>>
>>> Recently i had some ideas about radioimaging gene expression. There
>>> are many ways to study gene expression like using flourescent protien
>>> tags. but all those requires sacrificing the animal for taking tissue
>>> sections for immuno histochemistry. so i was searching some concepts
>>> for visualizing gene expression within specific tissues inside the
>>> body by some imaging techniques.Incidentally i came across bio
>>> activated contrast agents.You can see that in this link <link>http://
>>> www.nibib.nih.gov/HealthEdu/eAdvances/23Oct06<link>. But instead of
>>> using contrast agent i'm just curious to know is there anything like
>>> any protien or any biomolecule which is naturally radio opaque whose
>>> gene can be sandwiched with the promoter of the gene of interest and
>>> so we can image the the tissue and study the gene expression without
>>> killing the animal.....
>>
>> --www.indiebiotech.com
>> twitter.com/onetruecathal
>> joindiaspora.com/u/cathalgarvey
>> PGP Public Key:http://bit.ly/CathalGKey
>

--
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twitter.com/onetruecathal
joindiaspora.com/u/cathalgarvey
PGP Public Key: http://bit.ly/CathalGKey

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