Determination of Integrin Activity (ELISA-based)
| Materials | |||
|---|---|---|---|
| Wash solution | 1x PBS mit .0.0 5% BSA | ||
| Block solution | 2% BSA in 1 xPBS | ||
| Permeabilization solution | 0.1% Triton X-100 (0.1% in PBS) | ||
| Buffer for antibody | 0.1% BSA in x PBS | ||
| Reaction buffer | 10 ml Lösung B + 0.5 ml Lösung A | ||
| Solution A | 120 mg Tetramethylbenzidin in 5 ml Aceton + 45ml EtOH add 100µl H2O2 | ||
| Solution B | 30 mM potassium citrate, pH 4.1 | ||
| Starvation-medium | DMEM +0.5% CS | ||
| Suspension medium | DMEM + 0.25% BSA | ||
| Soybean-inhibitor | 0.5 mg/ml soybean trypsin in DMEM. |
Procedure
- Coat 96well-plates with e.g. collagen type1 or poly-Lysin over night
- serum starve cells (0.5% FCS) over night
- Next day cells are washed with 1x PBS, detached by limited trypsin/EDTA digestion, which is stopped by addition of soybean trypsin inhibitor
- pellet cells by centrifugation for 3min / 6000rpm (in the meantime cells are counted using the CASY)
- Detached cells are kept in suspension medium for 1 h at 37°C, and replated at 5 x 104 cells/well into wells coated with collagen.
- After 75 min cells were treated or not with 1M MnCl 1µl / well for about 5 min at 37°C and transferred to ice
- Cells are fixed with 4% paraformaldehyde in PBS for at least 30 min, washed with PBS and permeabilized with Triton X-100 for 15min
- cells are washed again 3 to 4 times with PBS and blocked with 2% BSA for 20 min
- cells are incubated with the mAbs 9EG7 (1:600) or AIIB2 (1:750) in blocking buffer to mark activated (9EG7) or total (AIIB2) β1 integrins.
- After incubation with the primary antibody, cells are washed with PBS, blocked 2% BSA for 20 min
- add secondary antibody (ProteinA-HRP or ProteinG-HRP) and incubate cells for 1h in the dark
- Wash and block cells for 20 min
- Start reaction: Cells are incubated with 100 μl / well of substrate solution (substrate solution is prepared by mixing 0.5 ml of TMB solution A with 10 ml solution B)
- The enzymatic colour reaction is stopped using 2 M H2SO4 (100μl/well) and the absorbance is determined at 450 nm.