RPA70 Rabbit Recombinant mAb

Western Blotting

Sample preparation

1. Aspirate media from cultures and Wash the cells with 1X PBS.
2. Lyse cells by adding 1X SDS sample buffer and transfer the extract to a microcentrifuge tube. Keep onice.
3. Sonicate for 10–15 sec to complete cell lysis and shear DNA.
4. Heat a 20 µl sample to 95–100°C for 5 min, then cool on ice.
5. Centrifuge for 5 min (with Microcentrifuge).
6. Load appropriate volumes of samples onto SDS-PAGE gel (loading quantity of protein sample depends on the concentration of extracted proteins).
NOTE: At the same time, please load the pre-stained molecular weight markers to determine molecular weights and verify electrotransfer.
7. Electrotransfer to nitrocellulose/PVDF membrane.

Membrane Blocking and Antibody Incubations

a. Blocking

1. (Optional) After transfer, wash the transferred membrane with TBS for 5 min at room temperature.
2. Incubate the membrane in the blocking buffer for 1 hr at room temperature.
3. Wash three times for 5 min each with TBST.

b. Antibodies Incubation

1. Incubate membrane and primary antibody (at the appropriate dilution and diluent recommended) in a primary antibody dilution buffer with gentle agitation overnight at 4°C.
2. Wash three times for 5 min each with TBST.
3. Incubate membrane with an appropriate second antibodydissolved in the blocking buffer with gentle agitation for 1 hr at room temperature.
4. Wash three times for 5 min each with TBST.
5. Proceed with detection.

Detection of Proteins

1. After antibodies incubation, Wash membrane three times for 5 minutes in TBST.
2. PrepareECL Reagent (or other chromogenic agents/substrate according to your second antibody). Mix well.
3. Incubate substrate with membrane for 1 minute, remove excess solution (membrane remains wet), wrap in plastic and expose to X-ray film.

Immunohistochemistry (Paraffin)

Deparaffinization/Rehydration

NOTE: Do not allow slides to dry at any time during this procedure.

1. Deparaffinize/hydrate sections:

1. Incubate sections in three washes of xylene for 5 min each.
2. Incubate sections in two washes of 100% ethanol for 10 min each.
3. Incubate sections in two washes of 95% ethanol for 10 min each.

2. Wash sections two times in dH2O for 5 min each.

Antigen retrieval

For Citrate: Heat slides in a microwave submersed in 1X citrate unmasking solution until boiling is initiated; continue with 10 min at a sub-boiling temperature (95°-98°C). Cool slides on bench top for 30 min.

Staining

1. Wash sections in dH2O three times for 5 min each.
2. Incubate sections in 3% hydrogen peroxide for 10 min.
3. Wash sections in dH2O two times for 5 min each.
4. Wash sections in wash buffer for 5 min.
5. Block each section with 100–400 µl of blocking solution for 1 hr at room temperature.
6. Remove blocking solution and add 100–400 µl primary antibody diluent in to each section. Incubate overnight at 4°C.
7. Remove antibody solution and wash sections with wash buffer three times for 5 min each.
8. Cover section with 1–3 drops HRPas needed. Incubate in a humidified chamber for 30 min at room temperature.
9. Wash sections three times with wash buffer for 5 min each.
10. Add DAB Chromogen Concentrate to DAB Diluent and mix well before use.
11. Apply 100–400 µl DAB to each section and monitor closely. 1–10 min generally provides an acceptable staining intensity.
12. Immerse slides in dH2O.
13. If desired, counterstain sections with hematoxylin.
14. Wash sections in dH2O two times for 5 min each.
15. Dehydrate sections:
1. Incubate sections in 95% ethanol two times for 10 sec each.
2. Repeat in 100% ethanol, incubating sections two times for 10 sec each.
3. Repeat in xylene, incubating sections two times for 10 sec each.
16. Mount sections with coverslips and mounting medium.

Immunofluorescence (Immunocytochemistry)

Specimen Preparation (forcultured cell lines, IF-IC)

1. Aspirate liquid, then cover cells to a depth of 2–3 mm with 4% formaldehyde diluted in 1X PBS.
NOTE: Formaldehyde is toxic, use only in a fume hood.
2. Fix cells for 15 min at room temperature.
3. Aspirate fixative, rinse three times in 1X PBS for 5 min each.
4. Proceed with Immunostaining.

Immunostaining

1. Add theblocking buffer and incubate for 60 min at RT.
2. Prepare primary antibody diluent in antibody dilution buffer as recommended .
3. Aspirate blocking solution, apply diluted primary antibody.
4. Incubate overnight at 4°C.
5. Rinse three times in 1X PBS for 5 min each.
6. Incubate specimens in fluorochrome-conjugated secondary antibody diluted in antibody dilution buffer for 1–2 hr at room temperature in the dark.
7. Rinse three times in 1X PBS for 5 min each.
8. Mount slides usingmounting medium with DAPI and cover with coverslips.
9. For best results, allow mountant to cure overnight at room temperature. For long-term storage, store slides flat at 4°C protected from light.