6. Immobilization of antibody onto gold surface
6-2. Using flow system
Immobilization of antibody onto gold surface might play a prime role to detect biomolecular (ex. Protein-Protein) interactions using SPR technology.
Appropriate immobilization and blocking of array chip could give a specific interaction with less non-specific responses. In this way, physical immobilization technique has been applied for various purposes in biological researches.
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Immobilization of anti-ovalbumin onto gold surface was performed in flow system through syringe pump, and obtained antibody absorption curve (Fig. 6.1)
Explanation of Fig. 6.1:
(i) Passes PBS buffer until getting a stable base line.
(ii) Then apply 1mg/ml of anti-ovalbumin and observe how the SPR angle changes with time.
Antibody supply is continued until showing a maximum antibody absorption curve.
(iii) Again passes PBS buffer to remove unbound antibody from the surface.
To avoid the non-specific binding, blocking the antibody-coated surface is performed. In general, BSA is used as a blocking buffer for antibody immobilization onto gold surface. Since here, we have used ovalbumin antibody, 0.5% alpha-casein is used as blocking buffer. After blocking, a complete immobilization pattern is shown in Fig. 6.2.
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Explanation of Fig. 6.2:
(i) After applying 0.5% casein, the angle changes of SPR signals increase and reach at maximum response.
(ii) Wash with PBS to remove excess blocking solutions from the surface.
| Catalog No. | Description |
| 012072 | Handy SPR PS-0109 |
| Components | |
| Transmission cable | |
| Power cable | |
| Software | |
| 011870 | Matching oil |
| 011869 | Gold chip |
| 011871 | PDMS flow cell |
