Purification of antibody Fab and F(ab′)2 fragments using Gradiflow technology

Prefractionation, enrichment, desalting and depleting of low volume and low abundance proteins and peptides using the MF10

The success of proteomics relies heavily in the ability to characterize very diverse species of proteins. This diversity stems from a proteins physicochemical properties, its copy number and abundance and its association with other proteins. Prefractionation and simplification of biological samples prior to downstream MS analysis is showing some virtue in obtaining greater depth of protein analysis. The MicroFlow MF10 is a prefractionation device for low volume, low abundance complex samples that can also enrich for very specific species of proteins based on charge and/or size either in native or denaturing format. It has also been used to desalt and deplete samples of contaminating ions or proteins. Although this instrument is only in its infancy in terms of exploring its capabilities, the technology has been used successfully for the fractionation of plasma proteins Wasinger(1), Omenn GS(2), as well as purification of human growth hormone Catzel D(3) antibodies Cheung(4) and IgY Gee(5) and other complex samples.

Fractionation of follicle stimulating hormone charge isoforms in their native form by preparative electrophoresis technology

Complex glycoprotein biopharmaceuticals, such as follicle stimulating hormone (FSH), erythropoietin and tissue plasminogen activator consist of a range of charge isoforms due to the extent of sialic acid capping of the glycoprotein glycans. Sialic acid occupies the terminal position on the oligosaccharide chain, masking the penultimate sugar residue, galactose from recognition and uptake by the hepatocyte asialoglycoprotein receptor. It is therefore well established that the more acidic charge isoforms of glycoprotein biopharmaceuticals have higher in vivo potencies than those of less acidic isoforms due to their longer serum half-life. Current strategies for manipulating glycoprotein charge isoform profile involve cell engineering or altering bioprocesss parameters to optimise expression of more acidic or basic isoforms, rather than downstream separation of isoforms. A method for the purification of a discrete range of bioactive recombinant human FSH (rhFSH) charge isoforms based on Gradiflowtrade mark preparative electrophoresis technology is described. Gradiflowtrade mark electrophoresis is scaleable, and incorporation into glycoprotein biopharmaceutical production bioprocesses as a potential final step facilitates the production of biopharmaceutical preparations of improved in vivo potency.

Efficient production, purification, and application of egg yolk antibodies against human HLA-A*0201 heavy chain and light chain (beta2m)

The importance of eggs as a source of specific antibodies is well recognized. Egg yolk contains 8--20mg immunoglobulins (IgY) per milliliter. However, the major problem in separating IgY is to remove the high concentrations of lipids in egg yolk. We first used water dilution method to get the supernatant containing IgY, then purified the antibody by caprylic acid-ammonium sulfate method, and obtained specific antibody with satisfactory purity and activity. By comparison of these several methods, each has its advantages, one can be chosen to purify IgY according to practical need. The purified IgY produced by the immunized chickens can stain the human peripheral blood mononuclear cell effectively when labeled with fluorescent FITC.