Cleaved-Caspase-9 p35 (D315) Polyclonal Antibody (ABP50010): Neo-Epitope Specificity for Apoptosis Initiation Research
The Caspase-9 Activation Problem: Total vs. Cleaved
Caspase-9 is the initiator caspase of the intrinsic apoptosis pathway. It exists as an inactive proenzyme (46 kDa) that, upon apoptosome assembly, undergoes autoproteolytic processing at D315 to generate the active p35 large subunit (35 kDa)[reference:21]. This cleavage is the molecular commitment point for mitochondrial apoptosis—the event that distinguishes a cell that will die from one that has merely received a death stimulus.
Yet antibodies raised against full-length caspase-9 or internal regions that are retained in the pro-form cannot distinguish the uncleaved zymogen from the active p35 fragment. A Western blot showing a 46-kDa band tells you caspase-9 is present; only a 35-kDa band tells you it has been activated.
Neo-Epitope Strategy: Cleavage-Site-Specific Recognition
Abbkine's Cleaved-Caspase-9 p35 (D315) Polyclonal Antibody (ABP50010) is engineered to solve this exact problem. The antibody is raised against a synthesized peptide derived from the internal region of human Caspase-9 p35 at amino acid range 240–320[reference:22]—a region exposed only after cleavage at D315. The product page explicitly states that the antibody detects endogenous levels of the fragment of activated Caspase-9 p35 protein resulting from cleavage adjacent to D315[reference:23].
Validated Performance and Specifications
| Application | Suggested Dilution |
|---|---|
| Western Blot | 1:500–1:2000 |
| IHC | 1:50–1:300 |
| Immunofluorescence | 1:50–1:300 |
| ELISA | Validated |
| Parameter | ABP50010 |
|---|---|
| Target | Cleaved Caspase-9 p35 (D315) |
| Host | Rabbit |
| Reactivity | Human, Rat, Mouse |
| Clonality | Polyclonal |
| Concentration | 1 mg/mL |
| Observed Molecular Weight | 35 kDa, 46 kDa |
| Formulation | PBS, 50% glycerol, 0.5% BSA, 0.02% sodium azide |
The dual observed bands (35 kDa and 46 kDa) are biologically meaningful: the 35-kDa band represents the active p35 fragment, while the 46-kDa band corresponds to the full-length pro-form that retains the epitope region. The ratio of 35-kDa to 46-kDa signal provides a direct readout of caspase-9 activation efficiency.
Head-to-Head: Cleaved Caspase-9 Antibody Comparison
| Feature | ABP50010 | Pan-Caspase-9 Antibodies |
|---|---|---|
| Specificity | Cleaved p35 (D315 neo-epitope) | Total caspase-9 (pro + cleaved) |
| Activation State Discrimination | Yes | No |
| Observed Bands | 35 kDa (cleaved) + 46 kDa (pro-form) | 46 kDa (pro-form only or pooled) |
| Applications | WB, IHC, IF, ELISA | Often WB only |
| Species Reactivity | Human, Rat, Mouse | Variable |
The Bottom Line
For apoptosis researchers who need to know whether caspase-9 has been activated—not merely whether the protein is present—ABP50010 delivers cleavage-specific, D315 neo-epitope precision. Whether you are studying chemotherapy-induced apoptosis in tumor models or developmental cell death in neuronal systems, this antibody lets you measure the commitment step itself.
📎 Reference: Cleaved-Caspase-9 p35 (D315) Polyclonal Antibody (ABP50010)
