[Histonet] catecholamine/glyoxylic acid fluoresence

[Chris Johnson]

Dear All,
 
I have recently been trying to show up sympathetic innervation of blood
vessels (noradrenaline/norepinephrine. I have used rat tail artery
(i.e., good sympathetic innervation) incubated in phosphate buffer and 2
% glyoxylic acid pH’d to 7.4 for 90 minutes followed 4 minutes at 100
ºC. At best I have seen very faint fluorescence with the very slightest
hint of a nerve plexus. I don’t think it is the processing as I have
used it successfully before and it seems to be fairly robust. I suspect
it is our filtering, but on looking at the literature, I’m not sure.  I
am using 
Excitation          380 – 400 nm
Dichromatic       440 nm high pass
Emission           455 – 485 nm
 
What are the emission characteristics of the fluorophore from this
reaction?
What am I doing wrong?!!!!
Any suggestions would be greatly appreciated!!
 
Best wishes,
 
Chris
 
 
Dr Christopher Johnson
Department of Physiology,
Medical Biology Centre, 
Queen's University of Belfast,
97 Lisburn Rd
Belfast BT7 9BL
02890 272092