20% Off Recombinant Proteins, Screening Libraries & Oligonucleotides
MedChemExpress (MCE) is proud to support scientific discovery with a limited-time promotion for our North American customers.
From July 1st, 2025, enjoy 20% off a wide selection of in-stock products essential for drug discovery and biomedical research.
Eligible Product Categories:
High-quality Recombinant Proteins.
Ready-to-use and customizable Compound Screening Libraries.
Reliable Oligonucleotides for molecular biology applications.
Why Choose MCE?
Rigorous quality control (HNMR, LC-MS, HPLC, bioactivity verification).
Extensive portfolio supporting cancer, immunology, neuroscience, and more.
Trusted by researchers worldwide.
Important Notes:
Offer valid from July 1, 2025, for customers in North America only.
Promotion applies to in-stock items only.
You will receive points and gifts based on your purchase amount.
Not valid with other offers or for purchases made through third-party platforms.
Recombinant Proteins
Over 12,000 recombinant proteins—ranging from cytokines and growth factors to enzymes and target proteins—rigorously validated for purity, activity, and consistency to ensure reproducible results.
Advantages of MCE Recombinant Proteins
High Purity: >95%, ensuring reliable performance.
Verified Bioactivity: Functionally validated in relevant assays.
Consistent Quality: Excellent lot-to-lot reproducibility.
Low Endotoxin Levels: <1 EU/μg, ideal for sensitive applications.
Flexible Packaging: Available in sizes from 2 μg to 1 mg.
Rapid Delivery: In-stock products shipped quickly.
Recombinant Proteins Products
Category Product Name
Cytokines and Growth Factors IL-2 IFN-gamma TGF beta 1
Immune Checkpoint Proteins PD-1 PD-L1 TIM-3/HAVCR2
CAR-T Related Proteins BCMA/TNFRSF17 CD19 CD38
CD Antigens CD3 epsilon CD8 beta IL-17RA
Fc Receptors FcRn IgE Fc gamma RIIIA/CD16
Receptor Proteins GLP1R TrkB Delta-like 4/DLL4
Enzymes & Regulators Cathepsin ACE2 Serine/Threonine Kinase
Complement System Complement C3/C3a Complement C5/C5a MASP-2
Ubiquitin Related Proteins UCHL1 USP14 KEAP1
Biotinylated Proteins PCSK9 (Biotinylated) PD-L1 (Biotinylated) CD79B (Biotinylated)
Viral Proteins RSV Glycoprotein SARS-CoV-2 MERS-CoV Spike/S1
GMP-grade Proteins GMP IL-1 alpha GMP IL-6 GMP GM-CSF
Fluorescent-labeled FITC-labeled CD47 PE-labeled Mesothelin FITC-labeled CD19
Animal-free Animal-Free IGF2 Animal-Free IL-10 Animal-Free IL-4
Product Scientific Data
IL-17F Protein, Human (HEK293, His)
Customer Validation: Proven Performance in Organoid Research

Cited in: Liu W, et al. Theranostics. 2024 May 27;14(8):3339-3357.

Recombinant proteins IL-22 (HY-P77969), 1L-17 (HY-P700194AF), and TNF-α (HY-P70800) were used to construct an organoid model of inflammation to simulate the inflammatory environment of psoriasis. KEGG analysis revealed significant enrichment of glucose metabolism in psoriatic lesions and of OXPHOS pathway in IL17RA+ basal cells.
Compound Screening Libraries
Special Discount for Large Orders
We provide the full-process drug development services covering compound library supply, screening services, lead compound optimization, and customized synthesis of compounds for preclinical and clinical studies.
Advantages of Compound Screening Libraries
Strict quality control and fresh-prepared.
Cherry-picked library without extra cost.
Full stock available for short lead time delivery.
No more wasted time in waiting compounds.
MCE Bioactive Compound Libraries
Different Libraries Meet Different Research Needs
• General Library Series
• Drug Repurposing Series
• Metabolic Library Series
• Natural Product Series
• Disease-related Series
• Classification by Structure Series
• Classification by Pathway Series
• Classification by Character Series
Hot-Selling Bioactive Compound Libraries
Product Name Number
Kinase Inhibitor Library 3,300+
Natural Product Library 5,000+
FDA-Approved Drug Library 3,200+
CNS-Penetrant Compound Library 1,000+
Human Endogenous Metabolite Compound Library 1,000+
Covalent Screening Library 1,500+
Macrocyclic Compound Library 400+
Lipid Compound Library 1,600+
Peptide Library 1,900+
PROTAC Library 400+
MCE Diversity Compound Libraries
MCE can offer 26+M screening compounds, including 80K lead-like diversity compounds, 16+M screening compounds and 10M MegaUni compounds can be synthesised using our in-stock building blocks. These compounds occupy a broad "chemical space," facilitating the discovery of diverse biological effects. They serve as powerful tools for new drug development and can be widely applied in high-throughput screening (HTS), virtual screening (VS), and AI-based screening.
Hot-Selling Diversity Compound Libraries
Product Name Number
Lead-like Diversity Library Plus 80,000
5K Scaffold Library 5,000
3D Diverse Fragment Library 5,000
Drug Fragment Library 1,168
Natural Product-like Compound Library 5,000
Lead-like Covalent Screening Library 1,000
RNA Binding Library 5,000
Molecular Glue-like Compound Library 300
Oligonucleotides
Oligonucleotides are composed of nucleotides with specially designed sequences. Oligonucleotides hybridize with the target gene mRNA or pre-mRNA through complementary base pairing, and can theoretically selectively regulate any target gene and protein expression. Currently, common oligonucleotides are antisense oligonucleotides (ASOs), siRNA (small interfering RNA), microRNA and aptamers, etc.
If customer need an siRNA kit for a specific target gene not listed, they can inquire with us. We'll evaluate the gene and launch the product, allowing customer to order and enjoy promotions.
29,000+ siRNAs (HY-RS)
Pre-designed siRNA Set contains three siRNAs for target gene (human, mouse, or rat), a negative control, a positive control, and a FAM-labeled negative control. We guarantee that at least one siRNA will silence the target mRNA by at least 70%. Customers must demonstrate transfection efficiency by achieving >80% knockdown with the positive control siRNA. If not, we will synthesize 3 new siRNAs for free.
Component Quantity Description
siRNA-1
siRNA-2
siRNA-3 		5 nmoL Three different siRNAs are designed for different regions of the target gene CDS.
siRNA Negative Control 5 nmoL Generally there is no homology between negative control sequence and the target gene sequence.
FAM-labeled siRNA Negative Control 5 nmoL It is used to detect the transfection efficiency of siRNA using fluorescence microscopy or flow cytometry.
GAPDH siRNA Positive Control 5 nmoL It is used to confirm that the RNAi experiments were performed correctly.
18,000+ miRNAs (HY-R/HY-RI)
MCE has developed miRNA mimic, miRNA inhibitor, miRNA agomir, and miRNA antagomir for studying miRNA function based on mature miRNA sequences of human, mouse, and rat in the miRBase database.
Category Characteristic Description
miRNA mimic Similar to endogenous miRNA duplex sequences, it can mimic endogenous miRNA. Transfection reagents are required, no need to construct vectors.
Suitable for cellular experiments.
miRNA inhibitor Specifically binds to mature miRNA and inhibits miRNA function.
miRNA agomir Similar to endogenous miRNA duplex sequences, it can mimic endogenous miRNA. Using special chemical modification and end labeling techniques to enhance its resistance to endonucleases degradation and strengthen its specificity and affinity to target miRNA.
It can also be administered to animals by injection or other methods.
miRNA antagomir Specifically binds to mature miRNA and inhibits miRNA function.
Oligonucleotide Synthesis
MCE owns a professional team and state-of-the-art facilities in synthesis and analysis of oligonucleotides. MCE can synthesize oligonucleotides (antisense oligonucleotide, siRNA, aptamer, etc.) according to customer’s requirement, carry out related testing procedures (purity, structure and stability analysis), and ensure accuracy and reproducibility of data with high-quality and efficient services.
Advantages

Various
Types

ASOs, siRNAs, miRNAs, aptamers, CpG ODNs, cap analogs, and probes, etc.

Comprehensive Modifications

2'-F, 2'-Ome,
2'-MOE, phosphorthioate (PS), locked nucleic acid (LNA), Cy3, and Cy5, etc.

Powerful
Capacity

MedChemExpress (MCE) has powerful synthesis platform with production capacity from mg to kg.

Reliable Quality Data

Use HPLC purification to guarantee over 90% product purity. Molecular weight deviation ≤1%.

Professional Technical Support

Professional technicians will answer your questions and solve your doubts for free.