Bax

Bax is a protein of the bcl-2 gene family. It promotes apoptosis by competing with bcl-2 proper. The Bax gene contains a small promoter element that complements a binding domain on the multi-faceted p53 tumor suppressor. Wild-type p53 has been demonstrated to upregulate the transcription of a chimeric reporter plasmid, utilizing the consensus promoter sequence of Bax approx. 50-fold over mutant p53. Mutations in this consensus sequence eliminate transcription of the reporter gene. Thus, it is likely that p53 promotes Bax’s apoptotic faculties in vivo as a primary transcription factor.

Bax exerts a pro-apoptotic rather than an anti-apoptotic effect on cells. Bax targets mitochondrial membranes, inducing mitochondrial damage and cell death in a caspase-independent manner. Bad plays a critical role in the Bax-mediated apoptosis pathway by dimerizing with BclxL, causing the displacement of Bax. The displacement of Bax allows apoptosis to proceed.

Bax is a mouse monoclonal antibody derived from cell culture supernatant that is concentrated, dialyzed, filter sterilized and diluted in buffer pH 7.5, containing BSA and sodium azide as a preservative.

1. Oltvai Z, et al. Cell. 1993:74,609-619
2. Miyashita T, Reed J, Cell. 1995:80,293-299

1. Cut and mount 3-4 micron formalin-fixed paraffin-embedded tissues on positive charged slides.
2. Air dry for 2 hours at 58° C.
3. Deparaffinize, dehydrate and rehydrate tissues.
4. Subject tissues to heat epitope retrieval using a suitable retrieval solution such as ImmunoDNA Retriever with Citrate (BSB 0020-BSB 0023) or EDTA (BSB 0030-BSB 0033).
5. Any of three heating methods may be used:
   • Electric Pressure Cooker
     Place standoff rack at base of pressure cooker. Add 1-2 inches of distilled water to the pressure cooker and turn heat to high, and incubate for 15 minutes. Open and immediately transfer slides to room temperature.
   • Water Bath Method
     Place tissues/slides in a pre-warmed staining dish or coplin jar containing the ImmunoDNA Retriever with Citrate or EDTA in a water bath set at 95°-99° C. Incubate for 30-60 minutes.
   • Conventional Steamer Method
     Place tissues/slides in a pre-warmed staining dish or coplin jar containing the ImmunoDNA Retriever with Citrate or EDTA in a Steamer, cover and steam for 30-60 minutes.
6. After heat treatment, transfer slides in ImmunoDNA Retriever with Citrate or EDTA to room temperature and let stand for 15-20 minutes.
7. Wash slides with IHC wash buffer or DI water.
8. Continue IHC staining protocol.