Source of hu-beta2-Microglobulin

[Fernando Garcia. LAB. C-208, CBM-CSIC, UAM, CANTOBLANCO28049-MADRID. T.3978040, FAX 3978344]

Dear Netters.

I am looking for sources of human-beta2-Microglobuline. In the past I have use 
it from Sigma but it becomes very expensive due the big amounts I am using.
 Suggestions are welcome.

Thanks in advance