The Glycosylation difference among EPO

[KS kim]

Dear Netters

The commercial product ,EPO, has a narrow band ( about 30 kD )on the  
SDS-PAGE, but the purified EPO from my lab. has a broad  band (22 - 30 
kD)on the gel. 

Does  the commercial EPO contain  homogeneous product by getting rid of 
less-glycosylated product with gel filteration chromatography, or can the 
homogeneous product be obtained from well-controlled culture condition?

THANK YOU