APC Human FOLR1 Protein (C-His)

Cat # Size Price Quantity
80270325 ug$245
802704100 ug$595

Product Details


ApplicationFlow Cytometry
FormatLiquid, APC
Expression HostCHO
Target NameFOLR-1, FBP, FOLR, FRα
SpeciesHuman
SourcesHuman FOLR1 (Arg25-Met233) with C-terminus His Tag is expressed in CHO cells and conjugated to APC.
Accession NumberP15328
Molecular WeightThe protein has a predicted molecular weight of 28.6 kDa. Under DTT-reducing conditions, it migrates at approximately 35-45 kDa on SDS-PAGE prior to conjugation.
Affinity TagC-His
Regulatory StatusRUO
Formulation1xPBS buffer, pH7.4, 0.09% NaN3 with a carrier protein
Endotoxin levelNot tested
Protein Concentration25µg size is bottled at 0.1mg/mL concentration. 100 µg size is bottled at lot specific concentration.
Storage and HandlingBriefly centrifuge the vial upon receipt. An unopened vial may be stored at 2–8°C for up to six months.
Research AreasEpithelial cells, Cancer Marker

Background Information


Folate receptor alpha (FOLR1), also known as FRα or folate receptor 1, is a high-affinity, glycosylphosphatidylinositol (GPI)-anchored cell surface protein primarily responsible for binding and internalizing folate and its derivatives. Folates are essential vitamins that participate in one-carbon metabolism, supporting nucleotide synthesis and methylation reactions crucial for DNA replication and repair. FOLR1 mediates cellular uptake of folate through receptor-mediated endocytosis, complementing the activity of other folate transporters such as the reduced folate carrier (RFC) and the proton-coupled folate transporter (PCFT).

Structurally, FOLR1 is a glycoprotein of approximately 38–42 kDa, composed of a single extracellular domain anchored to the plasma membrane via a GPI linkage. The extracellular domain contains a hydrophobic binding pocket that specifically recognizes and binds reduced folate and folate analogs with nanomolar affinity. Structural studies have revealed that this pocket is formed by β-sheets and loop regions that precisely accommodate the pterin and glutamate moieties of folate. The protein’s GPI anchor localizes it to lipid rafts, membrane microdomains involved in signaling and endocytosis, thereby facilitating efficient internalization and trafficking of folate-loaded vesicles.

FOLR1 has a particularly high expression in certain normal tissues, including the kidneys, placenta, and choroid plexus, but its expression in most normal epithelial tissues is limited. In contrast, FOLR1 is markedly overexpressed in several epithelial-derived cancers, such as ovarian, endometrial, breast, non–small cell lung, and renal carcinomas. This differential expression pattern plays a role in oncogenesis, as tumor cells exploit high folate uptake to support their increased proliferative demands. Moreover, FOLR1 expression correlates with tumor aggressiveness and poor prognosis in some cancers, making it a valuable biomarker for diagnosis and targeted therapy.

Therapeutically, FOLR1 serves as an attractive target for cancer treatment due to its selective tumor overexpression. Strategies exploiting this receptor include folate–drug conjugates (e.g., vintafolide), antibody–drug conjugates (ADCs) such as mirvetuximab soravtansine, and folate-based imaging agents for tumor detection. These therapies deliver cytotoxic agents specifically to FOLR1-positive cancer cells, minimizing off-target effects. Clinical trials have shown promising efficacy, particularly in ovarian cancers with high FOLR1 expression, establishing the receptor as a key biomarker and therapeutic target in precision oncology.

Data Sheets


APC Human FOLR1 Protein (C-His) TDS

Related Protocols


Flow Cytometry Protocol

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Frequently Asked Questions


How is a fluorescence labeled recombinant protein different from a labeled antibody for the same target?
A labeled protein (e.g., a fluorescent ligand or receptor domain) binds its natural counter-receptor or binding partner directly, making it useful for functional binding assays, competition/blocking studies, and receptor occupancy measurements — whereas an antibody typically binds a specific epitope regardless of the protein's natural binding activity. Choose the labeled protein format when you need to assess biologically relevant binding interactions rather than simple target detection.

Can these proteins be used in flow cytometry, and are they compatible with other panel reagents?
Yes, fluorescence labeled proteins are commonly used in flow cytometry panels to detect receptor expression or ligand binding on live cells, and are designed to be compatible with standard antibody panels. As with any multicolor panel, confirm spectral compatibility and run proper compensation controls when combining labeled proteins with labeled antibodies.

What controls should I use with fluorescence labeled recombinant proteins?
Recommended controls include an unlabeled/unconjugated version of the same protein (for competition/blocking controls), an irrelevant labeled protein of the same conjugate as a background control, and standard unstained/FMO controls for gating. Species- or format-matched controls are noted on the product page where available.

What applications are these proteins validated for?
Common applications include receptor binding assays, flow cytometry-based ligand-receptor studies, ELISA-based detection, and blocking/competition assays to study receptor occupancy or antagonist activity. Specific validated applications and recommended usage concentrations vary by product and are detailed on the individual product page.

Have a product or application question? Consult our FAQs or contact us.