Lane 1: Wild-type HAP1 cell lysate + Staurosporine (ab146588)  (1μM for 4h)
Lane 2: Wild-type HAP1 cell lysate
Lane 3: Caspase-3 knockout HAP1 cell lysate + Staurosporine (ab146588) (1μM for 4h)
Lane 4: Caspase-3 knockout HAP1 cell lysate

Lanes 1 - 4: Merged signal (red and green). Green - ab13847 observed at 17 kDa. Red - loading control, ab8245, observed at 37 kDa.

ab13847 was shown to recognise Caspase 3 when Caspase 3 knockout samples were used, along with additional cross-reactive bands. Wild-type and Caspase 3 knockout samples (±staurosporine treatment) were subjected to SDS-PAGE. ab13847 and ab8245 (loading control to GAPDH) were diluted to 1/500 and 1/10000 respectively and incubated overnight at 4°C. Blots were developed with Goat anti-Rabbit IgG H&L (IRDye® 800CW) preadsorbed (ab216773) and Goat anti-Mouse IgG H&L (IRDye® 680RD) preadsorbed (ab216776) secondary antibodies at 1/10000 dilution for 1 hour at room temperature before imaging.

All lanes : Anti-Caspase-3 antibody (ab13847) at 1 µg/ml

Lane 1 : Human Caspase 3 (active) Recombinant Protein
Lane 2 : Human Pro Caspase 3 (inactive) Recombinant Protein

Lysates/proteins at 0.1 µg per lane.

Secondary
All lanes : Goat Anti-Rabbit IgG H&L (HRP) (ab97051) at 1/10000 dilution

Developed using the ECL technique.

Performed under reducing conditions.

Predicted band size: 17, 34 kDa
Observed band size: 17,32 kDa why is the actual band size different from the predicted?


Exposure time: 8 minutes

Caspase 3 exist as inactive proenzymes which undergo proteolytic processing at conserved aspartic residues to produce large (17kDa) and small (12kDa) subunits. These subunits dimerize to form the active enzyme. ab13847 specifically detects the large active subunit (17kDa) and the  inactive pro Caspase 3 (32 kDa).

This blot was produced using a 4-12% Bis-tris gel under the MES buffer system. The gel was run at 200V for 35 minutes before being transferred onto a Nitrocellulose membrane at 30V for 70 minutes. The membrane was then blocked for an hour using 5% Bovine Serum Albumin before being incubated with ab13847 overnight at 4°C. Antibody binding was detected using an anti-rabbit antibody conjugated to HRP, and visualised using ECL development solution.

 

Secondary antibody - Goat Anti-Rabbit IgG H&L (HRP) (ab97051) secondary antibody

HeLa cells were fixed for 10 minutes at room temperature in 3.7% PFA and permeabilised in 0.1% Triton X-100/PBS then incubated with ab13847 (5µg/ml) for 1 hour at room temperature. The top panel shows control cells treated with DMSO. The bottom panel shows HeLa cells treated with 1 mM staurosporine (ab146588) for 4 hours to induce caspase-3 activation. ab13847 staining is shown in green and counterstaining with DAPI is shown in blue. 100x magnification.

The image shows the staining with ab13847 is very faint in the untreated control cultures,  but  very  bright  after  activation  of capsase-3 by treatment with  the staurosporine . (N.B. in these cultures the nuclei are apoptotic).