Photoaffinity labeling

Dr Engelbert Buxbaum engelbert_buxbaum at
Fri Oct 31 00:48:26 EST 2003

jmeyer1> wrote:

> Hello,
> I want to start an photoaffinity labeling experiment, unfortunately I 
> have no idea which light source will be sufficient for this purpose. I 
> want to use an Azidogroup (254nm)and a Benzoylgroup (366nm) as 
> photoactivateable structure. I compared the light sources given in 
> serveral papers. According th them everything from a 500W Xenon to a TLC 
> UV-cabinet can be used. The iinformation given is not very detailed 
> (Numeber ofWatts is missung etc,) so I am not to sure about that. Has 
> anyone any ideas/experience (...supplier)?
> Any hints will be greatly appreciated,
> thanx Jens
> PS The light source should be as inexpensive as possible ( always 
> when working at the university ;) )

It appears that the best results are obtained with high power flash
bulbs (1000 W and more). These can do the crosslinking fast. Low power
lamps require much more time, you get problems with sample heating,
evaporation and what have you. So its probably best to find somebody
with appropriate equipment and enter cooperation.

On the other hand, I have done croslinking of ATP to an ATPase with
nothing more than the sterilising light in a class II cabinet, the
sample was in a thin layer and kept on ice, with 10 min illumination
time giving maximum signal.

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