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To Purchase # 59949S

59949S 100 µl (50 tests) $299.00


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H Endogenous Rabbit IgG

Immunofluorescence (Immunocytochemistry)

Confocal immunofluorescent analysis of HCC1954 (left), MDA-MB-231 (middle) or A549 (right) using PD-L1 (Extracellular Domain Specific) (D8T4X) (Alexa Fluor® 594 Conjugate) Rabbit mAb (red). Blue pseudocolor = DRAQ5® #4084 (fluorescent DNA dye).

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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 goat serum (#5425) / 0.3% Triton™ X-100): To prepare 10 ml: add 0.5 ml normal goat serum and 0.5 ml 20X PBS to 9.0 ml dH2O, mix. 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. 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 datasheet 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. Coverslip slides with Prolong® Gold Antifade Reagent (#9071), Prolong® Gold AntiFade Reagent with DAPI (#8961).
  8. 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: 220

Product Usage Information

Application Dilutions
Immunofluorescence (Immunocytochemistry) 1:50

Storage: Supplied in PBS (pH 7.2), less than 0.1% sodium azide and 2 mg/ml BSA. Store at 4°C. Do not aliquot the antibody. Protect from light. Do not freeze.

Specificity / Sensitivity

PD-L1 (Extracellular Domain Specific) (D8T4X) Rabbit mAb (Alexa Fluor® 594 Conjugate) recognizes endogenous levels of total PD-L1 protein.

Species Reactivity: Human

Source / Purification

Monoclonal antibody is produced by immunizing animals with mammalian cells expressing full length PD-L1 protein.

Product Description

This Cell Signaling Technology antibody is conjugated to Alexa Fluor® 594 fluorescent dye and tested in-house for immunofluorescent analysis in human cells. The antibody is expected to exhibit the same species cross-reactivity as the unconjugated PD-L1 (Extracellular Domain Specific) (D8T4X) Rabbit mAb #86744.

Programmed cell death 1 ligand 1 (PD-L1, B7-H1, CD274) is a member of the B7 family of cell surface ligands that regulate T cell activation and immune responses. The PD-L1 ligand binds the PD-1 transmembrane receptor and inhibits T cell activation. PD-L1 was discovered following a search for novel B7 protein homologs and was later shown to be expressed by antigen presenting cells, activated T cells, and tissues including placenta, heart, and lung (1-3). Similar in structure to related B7 family members, PD-L1 protein contains extracellular IgV and IgC domains and a short, cytoplasmic region. Research studies demonstrate that PD-L1 is expressed in several tumor types, including melanoma, ovary, colon, lung, breast, and renal cell carcinomas (4-6). Expression of PD-L1 in cancer is associated with tumor infiltrating lymphocytes, which mediate PD-L1 expression through the release of interferon gamma (7). Additional research links PD-L1 expression to cancers associated with viral infections (8,9).

1.  Dong, H. et al. (1999) Nat Med 5, 1365-9.

2.  Freeman, G.J. et al. (2000) J Exp Med 192, 1027-34.

3.  Liang, S.C. et al. (2003) Eur J Immunol 33, 2706-16.

4.  Dong, H. et al. (2002) Nat Med 8, 793-800.

5.  Thompson, R.H. et al. (2006) Cancer Res 66, 3381-5.

6.  Pardoll, D.M. (2012) Nat Rev Cancer 12, 252-64.

7.  Taube, J.M. et al. (2012) Sci Transl Med 4, 127ra37.

8.  Lyford-Pike, S. et al. (2013) Cancer Res 73, 1733-41.

9.  Chen, B.J. et al. (2013) Clin Cancer Res 19, 3462-73.

Entrez-Gene Id 29126
Swiss-Prot Acc. Q9NZQ7

For Research Use Only. Not For Use In Diagnostic Procedures.
Cell Signaling Technology is a trademark of Cell Signaling Technology, Inc.
Alexa Fluor is a registered trademark of Life Technologies Corporation.
DRAQ5 is a registered trademark of Biostatus Limited.
The Alexa Fluor dye conjugates in this product are sold under license from Life Technologies Corporation, for research use only excluding use in combination with DNA microarrays and high content screening (HCS).
This product is provided under an intellectual property license from Life Technologies Corporation. The transfer of this product is contingent on the buyer using the purchased product solely in research, including use with HCS or other automated imaging applications but excluding use in combination with DNA microarrays. The buyer must not sell or otherwise transfer this product or its components for (a) diagnostic, therapeutic or prophylactic purposes; (b) testing, analysis or screening services, or information in return for compensation on a per-test basis; (c) manufacturing or quality assurance or quality control, or (d) resale, whether or not resold for use in research. For information on purchasing a license to this product for purposes other than as described above, contact Life Technologies Corporation, 5791 Van Allen Way, Carlsbad, CA 92008 USA or

PD-L1 (Extracellular Domain Specific) (D8T4X) Rabbit mAb (Alexa Fluor® 594 Conjugate)