Hi All,
I need everyone to put on their thinking caps for this!
I am a Sr. Staff Scientist and "old" PhD Protein Chemist for OSU and work as a protein scientist in their Mass Spec and Proteomics Department.
In the past year, we have identified various immunoprecipitated proteins as Glyceraldehyde 3-Phosphate Dehydrogenase! We have identified off of a matching gel of a client's western blot with a positive ID of GAPDH. So far, five labs looking for a specific protein from their specific pull-downs have had their proteins identified by MALDI and Orbitrap as GAPDH!
Is anybody else seeing their antibodies identifying GAPDH? Is this an artifact that has gone unnoticed??
Need Help!
Thanks so much,
Biokmst
0
2 replies to this topic
#2
bob1
-
- Global Moderators
-
- 4,350 posts
Thelymitra pulchella
224
Excellent
Excellent
Posted 25 August 2009 - 04:55 PM
We get cytokeratins rather than GAPDH.
Is there some contamination of your MS?
Is there some contamination of your MS?
#3
BIOKMST
-
- Active Members
-
- 14 posts
member
0
Neutral
Neutral
Posted 26 August 2009 - 04:48 AM
bob1, on Aug 25 2009, 04:55 PM, said:
We get cytokeratins rather than GAPDH.
Is there some contamination of your MS?
Is there some contamination of your MS?
Keratins are a popular contaminant and makes sense. GAPDH is more unusual and seems to come from gels that were western blot identified and IP samples, so it can't be a contaminant. Samples have been run between the identified runs on the orbitrap and showed no GAPDH!!
