[Histonet] Stability Guarantee vs Expiration date

[Hobbs, Carl]

Good info
I have always made 1/10 stocks of my abs ( in TBS/BSA/azide) and frozen aliquoted neat stocks.
For eg: I still use a 10 yr old "Dako" anti GFAP at 1/5000 ( stock 4C 1/10)
Sure, I am in research
Sure, I always add a positive control
Today I used a 5 yr old 1/10 4C of anti PCNA ( Abcam ab29)...worked as well as when I 1st made the 1/10 stock 
Sure....one has to keep checking by adding controls (  a known positive  like gut so that if crypt nuclei are exclusively +ve...OK)
Mind you.....PCNA is NOT a great prolif marker : far better to use anti Ki67
( half-life difference)
However, I wanted to see if Ki67/PCNA was good for worm Pwax sections ( former -ve, latter TOO positive)
Caveat: stored positive control sections can "go off"
Some call it "oxidation" of epitopes
It happens to some epitopes/ags
Best wishes, Histonet


Carl





Carl Hobbs FIBMS
Histology and Imaging Manager
Wolfson CARD
Guys Campus, London Bridge 
Kings College London
London
SE1 1UL
 


020 7848 6810