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PD-L1/CD274 Monoclonal antibody

PD-L1/CD274 Monoclonal Antibody for WB, IF, IHC, ELISA

Host / Isotype

Mouse / IgG1


human, mouse, pig, rat







Cat no : 66248-1-Ig


B7 H, B7 H1, B7 homolog 1, B7H1, CD274, CD274 molecule, PD L1, PDCD1 ligand 1, PDCD1L1, PDCD1LG1, PDL1, PD-L1, PD-L1/CD274, Programmed death ligand 1

Tested Applications

Positive WB detected inA375 cells, human placenta tissue, pig lung tissue, human skeletal muscle tissue, HepG2 cells, THP-1 cells, RAW 264.7 cells, A549 cells, K-562 cells, HSC-T6 cells
Positive IHC detected inhuman tonsillitis tissue, human heart tissue, human lung cancer tissue, human placenta tissue, mouse heart tissue
Note: suggested antigen retrieval with TE buffer pH 9.0; (*) Alternatively, antigen retrieval may be performed with citrate buffer pH 6.0
Positive IF detected inHeLa cells

Recommended dilution

Western Blot (WB)WB : 1:2000-1:10000
Immunohistochemistry (IHC)IHC : 1:5000-1:20000
Immunofluorescence (IF)IF : 1:50-1:500
It is recommended that this reagent should be titrated in each testing system to obtain optimal results.
Sample-dependent, Check data in validation data gallery.

Product Information

66248-1-Ig targets PD-L1/CD274 in WB, IP, IF, IHC, CoIP, ChIP, ELISA applications and shows reactivity with human, mouse, pig, rat samples.

Tested Reactivity human, mouse, pig, rat
Cited Reactivityhuman, mouse, rat
Host / Isotype Mouse / IgG1
Class Monoclonal
Type Antibody
Immunogen PD-L1/CD274 fusion protein Ag12443
Full Name CD274 molecule
Calculated Molecular Weight 290 aa, 33 kDa
Observed Molecular Weight 45-50 kDa
GenBank Accession NumberBC074984
Gene Symbol PD-L1
Gene ID (NCBI) 29126
Conjugate Unconjugated
Form Liquid
Purification MethodProtein A purification
Storage Buffer PBS with 0.02% sodium azide and 50% glycerol pH 7.3.
Storage ConditionsStore at -20°C. Stable for one year after shipment. Aliquoting is unnecessary for -20oC storage. 20ul sizes contain 0.1% BSA.

Background Information

PD-L1, also known as CD274 or B7H1, stands for programmed cell death ligand 1. It is a type I transmembrane protein that is thought to repress immune responses by binding to its receptor (PD1), thus inhibiting T-cell activation, proliferation, and cytokine production. It contains V-like and C-like immunoglobulin domains. PD-L1 expression is regulated by various cytokines, such as TNF-α or LPS (ISSN: 1848-7718). Increased expression of this protein in certain types of cancers, e.g., renal cell carcinoma or colon cancer, correlates with poor prognosis. 

What is the molecular weight of PD-L1? 

Depending on the isoform, the calculated molecular weight of the protein varies between 20 and 33 kDa (176-290 aa). 

What are the isoforms of PD-L1? 

According to NCBI, three different isoforms have been identified. There are significant differences in the untranslated and protein coding regions. 

What is the subcellular localization and tissue specificity of PD-L1? 

It is predicted to localize in the plasma membrane of various cell types, with a particularly high expression in placental trophoblast and subsets of immune cells. High levels of PD-L1 protein have also been detected in lung and colon tissues. 

What is the function of PD-L1 in immune responses? 

PD-L1 is critical for the induction and maintenance of immune self-tolerance during infection or inflammation in normal tissues. The interaction of PD-L1 and its receptors is responsible for preventing auto-immune phenotypes and balancing the overall immune response in situations such as pregnancy or tissue allografts. The interaction between PD-L1 and PD-1 or B7.1 starts an inhibitory signaling cascade, which results in the decreased proliferation of antigen-specific T-cells and increased survival of regulatory T-cells (PMID: 15240681). 

How can PD-L1's implication in cancer be used as a drug target? 

In certain tumors, high expression of PD-L1 serves as a stop-sign to inhibit the recognition of cancer cells by T-cells (PMID: 23087408). The interaction between PD-L1 and its receptors (PD1 and B7.1) is a mechanism for the tumor to evade the host immune response (PMID: 29357948). Several mAbs have been developed to target that interaction and thus prevent the inactivation of cytotoxic T-cells by the tumor (PMIDs: 23890059, 18173375).


Product Specific Protocols
WB protocol for PD-L1/CD274 antibody 66248-1-IgDownload protocol
IHC protocol for PD-L1/CD274 antibody 66248-1-IgDownload protocol
IF protocol for PD-L1/CD274 antibody 66248-1-IgDownload protocol
FC protocol for PD-L1/CD274 antibody 66248-1-IgDownload protocol
Standard Protocols
Click here to view our Standard Protocols



Cell Res

Targeting ATAD3A-PINK1-mitophagy axis overcomes chemoimmunotherapy resistance by redirecting PD-L1 to mitochondria

Authors - Xiao-Qing Xie


Developing Covalent Protein Drugs via Proximity-Enabled Reactive Therapeutics.

Authors - Qingke Li

Cancer Cell

ADORA1 Inhibition Promotes Tumor Immune Evasion by Regulating the ATF3-PD-L1 Axis.

Authors - Hong Liu

Cell Metab

NAD+ Metabolism Maintains Inducible PD-L1 Expression to Drive Tumor Immune Evasion.

Authors - Hongwei Lv

Bioact Mater

Gene engineered exosome reverses T cell exhaustion in cancer immunotherapy

Authors - Peishan Li

ACS Nano

Self-Assembly of Podophyllotoxin-Loaded Lipid Bilayer Nanoparticles for Highly Effective Chemotherapy and Immunotherapy via Downregulation of Programmed Cell Death Ligand 1 Production.

Authors - Rui Wang


The reviews below have been submitted by verified Proteintech customers who received an incentive forproviding their feedback.


hala (Verified Customer) (01-27-2023)

there is 2 bands one at the specific size and the other one is higher

  • Applications: Western Blot
  • Primary Antibody Dilution: 1/4000
  • Cell Tissue Type: hepG2
PD-L1/CD274 Antibody Western Blot validation (1/4000 dilution) in hepG2 (Cat no:66248-1-Ig)

Emma (Verified Customer) (11-29-2021)

Used for IF on FFPE prostate tissue at 1:50 with Tris-EDTA antigen retrieval (pH 9.0).

  • Applications: Immunofluorescence
  • Primary Antibody Dilution: 1:50
  • Cell Tissue Type: Prostate
PD-L1/CD274 Antibody Immunofluorescence validation (1:50 dilution) in Prostate (Cat no:66248-1-Ig)

Marina (Verified Customer) (06-14-2021)

HCC1937 breast cancer cells were fixed with 4% PFA, permeabilized and stained overnight at 4ºC with anti-PD-L1 Ig diluted 1:300. Nuclei were stained with DAPI.

  • Applications: Immunofluorescence
  • Primary Antibody Dilution: 1:300
  • Cell Tissue Type: Immortalized human breast cancer cells
PD-L1/CD274 Antibody Immunofluorescence validation (1:300 dilution) in Immortalized human breast cancer cells (Cat no:66248-1-Ig)