PLAP

Placental Alkaline Phosphatase (PLAP) is found in trophoblast cells of normal mature human placenta, Seminomas of testis and Ovarian Carcinomas. Detection of alkaline phosphatase in serum is a marker for Ovarian and Testicular Cancer. This antibody reacts with a membrane-bound isoenzyme of placental alkaline phosphatase occurring in the placenta during the 3rd trimester of gestation.

This antibody immunoreacts with Germ Cell Tumors and can discriminate between these and other neoplasms. Somatic neoplasms (e.g., breast, gastrointestinal, prostatic and urinary cancers) may also immunoreact with antibodies to PLAP. PLAP positivity, in conjunction with keratin negativity, favors Seminoma over Carcinoma. Germ Cell Tumors are usually keratin positive but they regularly fail to stain with EMA, whereas most Carcinomas stain with anti-EMA. This antibody has shown cross-reaction with human intestinal alkaline phosphatase.

PLAP is a rabbit 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.

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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.