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PREX1 (D8O8D) Rabbit mAb
Primary Antibodies
Monoclonal Antibody

PREX1 (D8O8D) Rabbit mAb #13168

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Citations (3)
  1. WB
  2. IF
Western Blotting Image 1 - PREX1 (D8O8D) Rabbit mAb

Western blot analysis of extracts from various cell lines using PREX1 (D8O8D) Rabbit mAb (upper) or GAPDH (D16H11) XP® Rabbit mAb #5174 (lower). Differential expression of PREX1 in breast cancer cells is consistent with that described by Sosa, M.S. et al. (2010).

Immunofluorescence Image 1 - PREX1 (D8O8D) Rabbit mAb

Confocal immunofluorescent analysis of MCF7 cells, treated with heregulin (10 ng/ml, 5 min; left) or heregulin (10 ng/ml, 5 min) and Wortmannin #9951 (1 μM, 1 hr; center), and MDA-MB-231 cells treated with heregulin (10 ng/ml, 5 min; right), using PREX1 (D8O8D) Rabbit mAb (green). Blue pseudocolor = DRAQ5® #4084 (fluorescent DNA dye).

To Purchase # 13168S
Product # Size Price
100 µl $ 268

Supporting Data

MW (kDa) 190, 110
Source/Isotype Rabbit IgG

Application Key:

  • W-Western
  • IP-Immunoprecipitation
  • IHC-Immunohistochemistry
  • ChIP-Chromatin Immunoprecipitation
  • IF-Immunofluorescence
  • F-Flow Cytometry
  • E-P-ELISA-Peptide

Species Cross-Reactivity Key:

  • H-Human
  • M-Mouse
  • R-Rat
  • Hm-Hamster
  • Mk-Monkey
  • Mi-Mink
  • C-Chicken
  • Dm-D. melanogaster
  • X-Xenopus
  • Z-Zebrafish
  • B-Bovine
  • Dg-Dog
  • Pg-Pig
  • Sc-S. cerevisiae
  • Ce-C. elegans
  • Hr-Horse
  • All-All Species Expected

Product Usage Information

Application Dilution
Western Blotting 1:1000
Immunofluorescence (Immunocytochemistry) 1:400


Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA, 50% glycerol and less than 0.02% sodium azide. Store at –20°C. Do not aliquot the antibody.



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Western Blotting Protocol

For western blots, incubate membrane with diluted primary antibody in 5% w/v BSA, 1X TBS, 0.1% Tween® 20 at 4°C with gentle shaking, overnight.

NOTE: Please refer to primary antibody product webpage for recommended antibody dilution.

A. Solutions and Reagents

From sample preparation to detection, the reagents you need for your Western Blot are now in one convenient kit: #12957 Western Blotting Application Solutions Kit

NOTE: Prepare solutions with reverse osmosis deionized (RODI) or equivalent grade water.

  1. 20X Phosphate Buffered Saline (PBS): (#9808) To prepare 1 L 1X PBS: add 50 ml 20X PBS to 950 ml dH2O, mix.
  2. 10X Tris Buffered Saline (TBS): (#12498) To prepare 1 L 1X TBS: add 100 ml 10X to 900 ml dH2O, mix.
  3. 1X SDS Sample Buffer: Blue Loading Pack (#7722) or Red Loading Pack (#7723) Prepare fresh 3X reducing loading buffer by adding 1/10 volume 30X DTT to 1 volume of 3X SDS loading buffer. Dilute to 1X with dH2O.
  4. 10X Tris-Glycine SDS Running Buffer: (#4050) To prepare 1 L 1X running buffer: add 100 ml 10X running buffer to 900 ml dH2O, mix.
  5. 10X Tris-Glycine Transfer Buffer: (#12539) To prepare 1 L 1X Transfer Buffer: add 100 ml 10X Transfer Buffer to 200 ml methanol + 700 ml dH2O, mix.
  6. 10X Tris Buffered Saline with Tween® 20 (TBST): (#9997) To prepare 1 L 1X TBST: add 100 ml 10X TBST to 900 ml dH2O, mix.
  7. Nonfat Dry Milk: (#9999).
  8. Blocking Buffer: 1X TBST with 5% w/v nonfat dry milk; for 150 ml, add 7.5 g nonfat dry milk to 150 ml 1X TBST and mix well.
  9. Wash Buffer: (#9997) 1X TBST.
  10. Bovine Serum Albumin (BSA): (#9998).
  11. Primary Antibody Dilution Buffer: 1X TBST with 5% BSA; for 20 ml, add 1.0 g BSA to 20 ml 1X TBST and mix well.
  12. Biotinylated Protein Ladder Detection Pack: (#7727).
  13. Prestained Protein Marker, Broad Range (11-190 kDa): (#13953).
  14. Blotting Membrane and Paper: (#12369) This protocol has been optimized for nitrocellulose membranes. Pore size 0.2 µm is generally recommended.
  15. Secondary Antibody Conjugated to HRP: Anti-rabbit IgG, HRP-linked Antibody (#7074).
  16. Detection Reagent: SignalFire™ ECL Reagent (#6883).

B. Protein Blotting

A general protocol for sample preparation.

  1. Treat cells by adding fresh media containing regulator for desired time.
  2. Aspirate media from cultures; wash cells with 1X PBS; aspirate.
  3. Lyse cells by adding 1X SDS sample buffer (100 µl per well of 6-well plate or 500 µl for a 10 cm diameter plate). Immediately scrape the cells off the plate and transfer the extract to a microcentrifuge tube. Keep on ice.
  4. Sonicate for 10–15 sec to complete cell lysis and shear DNA (to reduce sample viscosity).
  5. Heat a 20 µl sample to 95–100°C for 5 min; cool on ice.
  6. Microcentrifuge for 5 min.
  7. Load 20 µl onto SDS-PAGE gel (10 cm x 10 cm).

    NOTE: Loading of prestained molecular weight markers (#13953, 5 µl/lane) to verify electrotransfer and biotinylated protein ladder (#7727, 10 µl/lane) to determine molecular weights are recommended.

  8. Electrotransfer to nitrocellulose membrane (#12369).

C. Membrane Blocking and Antibody Incubations

NOTE: Volumes are for 10 cm x 10 cm (100 cm2) of membrane; for different sized membranes, adjust volumes accordingly.

I. Membrane Blocking

  1. (Optional) After transfer, wash nitrocellulose membrane with 25 ml TBS for 5 min at room temperature.
  2. Incubate membrane in 25 ml of blocking buffer for 1 hr at room temperature.
  3. Wash three times for 5 min each with 15 ml of TBST.

II. Primary Antibody Incubation

  1. Incubate membrane and primary antibody (at the appropriate dilution and diluent as recommended in the product webpage) in 10 ml primary antibody dilution buffer with gentle agitation overnight at 4°C.
  2. Wash three times for 5 min each with 15 ml of TBST.
  3. Incubate membrane with Anti-rabbit IgG, HRP-linked Antibody (#7074 at 1:2000) and anti-biotin, HRP-linked Antibody (#7075 at 1:1000–1:3000) to detect biotinylated protein markers in 10 ml of blocking buffer with gentle agitation for 1 hr at room temperature.
  4. Wash three times for 5 min each with 15 ml of TBST.
  5. Proceed with detection (Section D).

D. Detection of Proteins

Directions for Use:

  1. Wash membrane-bound HRP (antibody conjugate) three times for 5 minutes in TBST.
  2. Prepare 1X SignalFire™ ECL Reagent (#6883) by diluting one part 2X Reagent A and one part 2X Reagent B (e.g. for 10 ml, add 5 ml Reagent A and 5 ml Reagent B). 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.

* Avoid repeated exposure to skin.

posted June 2005

revised June 2020

Protocol Id: 10

Immunofluorescence (Immunocytochemistry)

A. Solutions and Reagents

NOTE: Prepare solutions with reverse osmosis deionized (RODI) or equivalently purified water.

  1. 20X Phosphate Buffered Saline (PBS): (9808) To prepare 1L 1X PBS: add 50 ml 20X PBS to 950 ml dH2O, mix. Adjust pH to 8.0.
  2. Formaldehyde: 16%, methanol free, Polysciences, Inc. (cat# 18814), use fresh and store opened vials at 4°C in dark, dilute in 1X PBS for use.
  3. Methanol, 100%
  4. Blocking Buffer (1X PBS / 5% normal serum / 0.3% Triton™ X-100): To prepare 10 ml, add 0.5 ml normal serum from the same species as the secondary antibody (e.g., Normal Goat Serum (#5425)) and 0.5 mL 20X PBS to 9.0 mL dH2O, mix well. While stirring, add 30 µl Triton™ X-100.
  5. Antibody Dilution Buffer (1X PBS / 1% BSA / 0.3% Triton X-100): To prepare 10 ml, add 30 µl Triton™ X-100 to 10 ml 1X PBS. Mix well then add 0.1 g BSA (9998), mix.
  6. Recommended Fluorochrome-conjugated Anti-Rabbit secondary antibodies:

  7. Prolong® Gold AntiFade Reagent (#9071), Prolong® Gold AntiFade Reagent with DAPI (#8961).

B. Specimen Preparation - Cultured Cell Lines (IF-IC)

NOTE: Cells should be grown, treated, fixed and stained directly in multiwell plates, chamber slides or on coverslips.

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

C. Immunostaining

NOTE: All subsequent incubations should be carried out at room temperature unless otherwise noted in a humid light-tight box or covered dish/plate to prevent drying and fluorochrome fading.

  1. Methanol Permeabilization Step: Cover cells with ice-cold 100% methanol (use enough to cover completely to a depth of 3–5 mm, DO NOT LET DRY), incubate in methanol for 10 minutes at –20°C, rinse in 1X PBS for 5 minutes.
  2. Block specimen in Blocking Buffer for 60 minutes.
  3. While blocking, prepare primary antibody by diluting as indicated on product webpage in Antibody Dilution Buffer.
  4. Aspirate blocking solution, apply diluted primary antibody.
  5. Incubate overnight at 4°C.
  6. Rinse three times in 1X PBS for 5 minutes each.
  7. Incubate specimen in fluorochrome-conjugated secondary antibody diluted in Antibody Dilution Buffer for 1–2 hours at room temperature in dark.
  8. Rinse in 1X PBS as in step 6.
  9. Coverslip slides with Prolong® Gold Antifade Reagent (#9071), Prolong® Gold AntiFade Reagent with DAPI (#8961).
  10. For best results examine specimens immediately using appropriate excitation wavelength. For long term storage, store slides flat at 4°C protected from light.

posted November 2006

revised December 2010

Protocol Id: 32

Specificity / Sensitivity

PREX1 (D8O8D) Rabbit mAb recognizes endogenous levels of total PREX1 protein. This antibody will recognize both isoform 1 (190 kDa) and isoform 2 (110 kDa) human PREX1, but has not been observed to cross-react with human PREX2 protein.

Species Reactivity:

Human, Monkey

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic peptide corresponding to residues surrounding His770 of human PREX1 protein.


Phosphoinositide-3,4,5-triphosphate (PtdIns(3,4,5)P3)-dependent Rac exchanger 1 (PREX1) is a Rac-specific GTP-exchange factor (GEF) regulated by heterotrimeric G-protein β/γ subunits and the lipid second messenger PtdIns(3,4,5)P3 (1-4). PREX1 contains two DEP (Dishevelled, Egl-10, and Pleckstrin homology) domains that coordinate heterotrimeric G-protein signaling. It also contains a Dbl-homology domain, which exhibits Rac-GEF activity, and PH and PDZ domains for interacting with upstream and downstream signaling components (1). Originally shown to modulate cellular migration of neutrophils by Rac2 activation (5-8), it is clear that PREX1 plays a broader role in modulating cell migration. PREX1 promotes metastasis of prostate cancer and melanoma cells, affects endothelial junction integrity, and is required for platelet generation and function (9-14). Research studies suggest that PREX1 plays an essential role in mediating ErbB-dependent signaling events in breast cancer by coordinating Rac activation in response to paracrine signals within the tumor microenvironment. Activation of PREX1 downstream of ErbB3 and EGFR chemokine receptors (CXCR4) promotes Rac activation, increased migration, proliferation, tumorigenesis, and metastasis in breast cancer cells (15,16). Consistent with this observation, deletion of PREX1 expression in mice results in resistance to melanoma metastasis (11). Expression of PREX1 in human tumors transplanted into mice inversely correlates with increased tumor progression and poor survival (15). Additional research studies suggest that PREX Rac-GEF activity is enhanced by phosphorylation in response to growth factors or hormones, and may require coincident dephosphorylation of two PH domain serine residues. The upstream kinases and precise regulatory mechanism remains elusive (15,17).

  1. Welch, H.C. et al. (2002) Cell 108, 809-21.
  2. Hill, K. et al. (2005) J Biol Chem 280, 4166-73.
  3. Mayeenuddin, L.H. and Garrison, J.C. (2006) J Biol Chem 281, 1921-8.
  4. Barber, M.A. et al. (2007) J Biol Chem 282, 29967-76.
  5. Welch, H.C. et al. (2005) Curr Biol 15, 1867-73.
  6. Dong, X. et al. (2005) Curr Biol 15, 1874-9.
  7. Zhao, T. et al. (2007) J Leukoc Biol 81, 1127-36.
  8. Nie, B. et al. (2010) Cell Signal 22, 770-82.
  9. Qin, J. et al. (2009) Oncogene 28, 1853-63.
  10. Wong, C.Y. et al. (2011) J Biol Chem 286, 25813-22.
  11. Lindsay, C.R. et al. (2011) Nat Commun 2, 555.
  12. Qian, F. et al. (2012) Arterioscler Thromb Vasc Biol 32, 768-77.
  13. Naikawadi, R.P. et al. (2012) Circ Res 111, 1517-27.
  14. Campbell, A.D. et al. (2013) PLoS One 8, e53982.
  15. Montero, J.C. et al. (2011) Oncogene 30, 1059-71.
  16. Sosa, M.S. et al. (2010) Mol Cell 40, 877-92.
  17. Montero, J.C. et al. (2013) Cell Signal 25, 2281-9.

Pathways & Proteins

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For Research Use Only. Not For Use In Diagnostic Procedures.
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