Technical Data
Protein A (Sepharose)
Molecular Biology Storage: 4°C Do not freezeShipping: Blue Ice
Protein A is a highly stable surface receptor produced by Staphylococcus aureus, which is capable of binding the Fc portion of immunoglobulins, especially IgGs, from a large number of species (Boyle and Reis, 1987). Each protein A molecule can bind 2 molecules of IgG, allowing the formation of a precipitate (Sjöholm, 1975).

Protein A Sepharose is prepared by covalently coupling Protein A to 6% cross-linked sepharose beads. The coupling technique is optimized to give a high binding capacity for IgG. The capacity of IgG binding could be up to 25mg of human IgG per ml of wet gel. High binding capacity (18-22mg/ml of gel); High flow rate; Low falling off of rProtein A.

Purification of monoclonal and polyclonal antibodies. Protein A binds to most human and mouse IgG subclasses (e.g., human IgG1, IgG2, IgG4; mouse IgG1, IgG2a, IgG2b, IgG3). It also binds to total IgG from cow, guinea pig, hamster, horse, pig, and rabbit. Protein A has little affinity to chicken, goat, rat and sheep.

1. Wash column with ddH2O to remove air bubbles.
2. Fill column with protein A beads.
3. Wash the column with 5X volume of Binding Buffer.
4. Dilute serum sample with Binding Buffer (1:1 ratio).
5. Invert the diluted serum sample to mix well. Make sure no bubbles in the solution.
6. Pour the solution onto the column.
7. Collect the solution and repeat step 6 & 7 for 10 times.
8. Wash the column 5-10 times with the Binding Buffer.
9. Add Elution Buffer to elute IgG (0.5-1ml each time).
10. Collect the eluent using microcentrifuge tube.
11. Repeat step 9 & 10 for 10 times.
12. Assay protein concentration and combine the fractions containing sufficient amount of IgG.

Binding buffer: 0.05M sodium borate, 0.15M sodium chloride pH 8.0
Elution buffer: 0.1M citric acid, pH 2.75

Storage and Stability:
Slurry may be stored at 4°C. Do Not Freeze.
Form: Supplied as a 50% slurry in 0.01% Thimerosal/H2O, 5mg Protein A/ml Sepharose beads.

Important Note: This product as supplied is intended for research use only, not for use in human, therapeutic or diagnostic applications without the expressed written authorization of United States Biological.
Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.