Recombinant human GCSF Receptor protein (Fc Chimera) (ab83994)

Each separate size is filled separately so that the target amount of protein of the primary product is maintained.
When each is brought to 0.5ml, each will have only 1% HSA and 10% sugar as a stabilizer. The 25ug size will be 25ug/500ul and the 50ug will be 50ug/500ul, the amount of sugar and HSA is constant in both but the target protein is less in the 25ug size obviously, since the "mass" of the target is matched to the size run.
You can combine both formats into a single stock and you would have approximately 75ug/1mL of target protein that way, probably much easier to figure and work with than changing between the two sizes.

"We have our specification that was used to pass the current batch of material. The material would not have been released if it had not worked at the time of release and I've never had any complaints or reason to suspect otherwise.
Our specification is:
The ED50 of G-CSF R – Fc Chimera is typically 2-3 ng/ml as measured by its ability to neutralize G-CSF mediated proliferation of the murine myeloblastic m-NFS-60 cell line.
The chimera's are tested only by their ability to block G-CSF stimulation --note we are using our own G-CSF in the assay, other manufacture's materials may require different amounts of the chimera."

The source of the GCSF Receptor protein ab83994 informed me that :
With regards to any of our proteins actually binding HSA, no we do not have any data, and I suppose one could get some minor binding just due to protein-protein interactions since the amount of HSA is rather high and it is there to stabilize the protein but I do not put that sort of interaction in the same class as say a true "binding" where there is a specific avidity for HSA. But we've never examined it and so far it certainly hasn't been a huge factor in the activity assays for any of the proteins we offer.

Now as for dimerization, all we know is that our Fc fusions do what they are supposed to do.
G-CSF R is produced as an ECD-Fc fusion protein with the aim of enhancing its ativity. ECD-Fc fusion proteins have an advantage over soluble receptors because many receptors are only functional in dimeric form. Fusion to the Fc domain of IgG1 induces dimerization due to the ability of the Fc domain to form disulfide bonds. The resulting dimeric receptor ECD-Fc mimics the activated form of the receptor and possess enhanced affinity for its cognate ligand relative to its monomeric form. For a comprehensive review please see Avalos BR (1996) Blood 88(3): 761-777.

With this particular product we test only the the ability of the fusion protein to bind the target and inhibit proliferation, since it does that we are confident that the ECD domain is intact; we have not compared that activity to non-Fc fusion forms so we cannot truly say if the Fc is providing additional efficacy but studying the literature our IgG domain should function as expected so we would expect so. Unfortunately we do not have any data or graphs available.

Thank you for your inquiry.

I can confirm that 10% Trehalose and 1% Human serum albumin are contained in the lyophilized product.

Please follow the instructions on the datasheet for reconstitution.

I hope this information is helpful and wish you good luck with your research.