Cell Culture

<h2 data-section-id="pdko8n" data-start="0" data-end="50">What are recombinant proteins for cell culture?</h2>
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Recombinant proteins for cell culture are biologically active growth factors, cytokines, and signaling molecules produced using recombinant DNA technology to control specific cellular functions in vitro. Growth factors such as FGF (fibroblast growth factor), EGF (epidermal growth factor), and TGF-&beta; (transforming growth factor beta) regulate cell growth, proliferation, survival, and differentiation. Cytokines including IL-2, IL-7, IL-15, and IL-21 influence immune cell activation, expansion, and function. These proteins are widely used in serum-free and chemically defined media, stem cell and iPSC culture, immune cell expansion, organoid development, hybridoma production, and cell and gene therapy workflows where precise control over cellular signaling is required.
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<h2 dir="ltr">What you will find:</h2>
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<ul>
<li>Includes cytokines, chemokines, growth factors, and signaling proteins to support proliferation, differentiation, and maintenance of&nbsp;mammalian cells</li>
<li>Rat, human, and mouse recombinant proteins compatible with translational research models and diverse mammalian cell culture&nbsp;</li>
<li>Optimizing cell metabolic activity, signalling pathways, and experimental reproducibility in vitro using recombinant proteins&nbsp;</li>
<li>Suitable for organoid development, expansion of cells, activation of immune cells, neuronal studies, and protein expression workflow optimization.</li>
</ul>
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<h2 data-section-id="4x59d8" data-start="1050" data-end="1118">How to choose recombinant proteins, cytokines, and growth factors</h2>
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Quality grade: RUO vs. preclinical vs. GMP
Research-use-only (RUO) proteins are suitable for most academic and industrial research applications. Preclinical-grade proteins provide enhanced documentation and quality control for studies supporting clinical development. GMP-grade proteins are manufactured under controlled quality systems with complete traceability and lot-to-lot bioactivity verification, making them appropriate for cell therapy, gene therapy, and other regulated applications.
Expression system and post-translational modifications
The production system can significantly affect protein activity. HEK293 and other mammalian expression systems preserve native human post-translational modifications such as glycosylation and phosphorylation, which are often necessary for full biological function. Bacterial expression systems such as E. coli may offer lower cost and higher yields but cannot reproduce many of these modifications.
Carrier-free formulation
Carrier-free recombinant proteins are formulated without stabilizing proteins such as bovine serum albumin (BSA). This eliminates potential experimental interference from carrier proteins and supports serum-free, animal-component-free, and GMP-compatible workflows. Carrier-free formulations are especially important when studying sensitive signaling pathways or developing clinical manufacturing processes.
Endotoxin level and purity
Endotoxins can stimulate inflammatory responses and alter cell behavior, particularly in immune cell cultures. For T-cell expansion, stem cell culture, and other sensitive applications, low-endotoxin or endotoxin-free proteins with documented purity above 95% are preferred to ensure reproducible results.
Stability format: standard vs. thermostable
Standard recombinant proteins gradually lose activity during prolonged incubation at 37&deg;C. Thermostable variants, such as engineered FGF2 formulations, maintain biological activity for longer periods and reduce the need for frequent media supplementation. These products can improve workflow efficiency in stem cell maintenance and differentiation protocols.
Storage and reconstitution
Lyophilized recombinant proteins offer extended shelf life and are typically stored frozen until use. After reconstitution, proteins should be aliquoted into single-use portions whenever possible to minimize repeated freeze-thaw cycles that can reduce activity. Proper storage conditions vary by product and should follow the manufacturer's recommendations.
<h2 data-section-id="rxnuuy" data-start="3659" data-end="3704">&nbsp;</h2>
<h2 data-section-id="1fljvas" data-start="4451" data-end="4476">Specifications context</h2>
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Modern recombinant cytokines and growth factors are available in a wide range of formats including carrier-free, low-endotoxin, animal-component-free, and GMP-grade formulations. Many GMP-grade cytokines such as IL-2, IL-7, IL-15, and IL-21 undergo lot-specific bioactivity testing using validated reference standards to ensure consistent biological performance. Mammalian-cell-expressed proteins are increasingly preferred for applications requiring native structure and maximum biological activity.
As of 2026, carrier-free, low-endotoxin recombinant proteins produced in mammalian expression systems have become the preferred choice for stem cell culture, immune cell expansion, organoid development, and advanced biomanufacturing workflows.
For basal media used alongside recombinant proteins, see Classic Media. For additional supplementation reagents, see Cell Culture Supplements &amp; Additives. Browse Mammalian Cell Culture for the broader category.
<a href="https://mbpinc.net/contact-us">Contact the expert team</a> at MBP today and get optimized recombinant proteins for your lab.

Recombinant Proteins

MSDS

Growth Factor-eFlyer

Growth Factors and Cytokines-Brochure

Growth Factors and Cytokines-FAQ

Role of Growth Factors in Cell Differentiation-Poster

Recombinant Mouse IL1B

Z200105 by Applied Biological Materials is recombinant mouse IL1B (IL-1 beta, M. musculus), a tag-free pro-inflammatory cytokine expressed in E. coli. At 17 kDa with &gt;95% purity, endotoxin &lt;1.0 EU/µg, and ED50 ≤2.0 pg/mL (specific activity ≥5.0 × 10⁸ units/mg), it is suitable for NLRP3 inflammasome, NF-kB, and neuroinflammation research. Lyophilized from 0.2 µm filtered PBS, pH 7.

Organism

Family

Aliases

Gene Symbol

Gene ID

Accession Number

Source

Species

Appearance

Molecular Weight

Endotoxin Level

Purity

Formulation

Function

Reconstitution

Storage

Usage

Manufacturer

Shipping Condition

Storage Condition

Recombinant Mouse IL1B, 10 µg

Recombinant Mouse IL1B, 100 µg

Recombinant Mouse IL1B, 1.0 mg

Recombinant Mouse IL2

Recombinant Mouse IL-2 (Z200135) by ABM — 17 kDa, E. coli, Mouse (M. musculus), &gt;95% purity, tag-free. CTLL-2 ED50 &lt;0.1 ng/mL. T cell proliferation, Treg expansion, and NK cell research.

Recombinant Mouse IL2, 20 µg

Recombinant Mouse IL2, 100 µg

Recombinant Mouse IL2, 1.0 mg

Recombinant Mouse IL25

Z200255 by Applied Biological Materials is Recombinant Mouse IL-25 (IL-17E), a 16 kDa E. coli-expressed, tag-free cytokine (10 µg lyophilized) with &gt;95% purity by SDS-PAGE, endotoxin &lt;1.0 EU/µg (LAL), and bioactivity ED50 &lt;0.5 ng/mL — for type 2 immunity, allergy, and mucosal immunology research. UniProt Q9CPT4.

Recombinant Mouse IL25, 10 µg

Recombinant Mouse IL25, 100 µg

Recombinant Mouse IL25, 1.0 mg

Recombinant Mouse IL3

Recombinant Mouse IL-3 (Z200145) by ABM — 15 kDa, E. coli, Mouse (M. musculus), &gt;95% purity, tag-free. M-NFS-60 ED50 &lt;0.05 ng/mL. Hematopoiesis and mast cell research.

Recombinant Mouse IL3, 10 µg

Recombinant Mouse IL3, 1.0 mg

Recombinant Mouse IL33

Recombinant Mouse IL-33 Z200155 by ABM—tag-free, E. coli-expressed IL-1 family alarmin, 18 kDa, &gt;95% purity, ED50 ≤0.3 ng/mL. Available from MBP INC.

Recombinant Mouse IL33, 10 µg

Recombinant Mouse IL33, 100 µg

Recombinant Mouse IL33, 1.0 mg

Recombinant Mouse IL4

Recombinant Mouse IL4 (Z200165) by ABM — 14 kDa E. coli-expressed Th2 cytokine, >95% pure, ED50 ≤0.4 ng/mL, BSF-1. Order from MBP INC.

Recombinant Mouse IL4, 10 µg

Recombinant Mouse IL4, 1.0 mg

Recombinant Mouse IL5

Z200475 by Applied Biological Materials (ABM) is a recombinant mouse IL-5 expressed in insect cells, 13 kDa, tag-free, with greater than 95% purity by SDS-PAGE and endotoxin below 1.0 EU/µg. ED50 ≤0.2 ng/mL in TF-1 cell proliferation assay; specific activity ≥6.0 × 10⁶ units/mg.

Unit Quantity

Recombinant Mouse IL6

Recombinant Mouse IL-6 (Z200175) by ABM — 22 kDa, E. coli, Mouse (M. musculus), &gt;95% purity, tag-free. Hybridoma ED50 &lt;0.05 ng/mL. JAK/STAT3, Th17, and B cell research.

Recombinant Mouse IL6, 10 µg

Recombinant Mouse IL6, 100 µg

Recombinant Mouse IL6, 1.0 mg

Recombinant Mouse IL7

Recombinant Mouse IL-7 Z200645 by ABM: 15.2 kDa non-glycosylated E. coli-expressed hematopoietic growth factor, &gt;95% purity by SDS-PAGE, &lt;1.0 EU/µg endotoxin. 10 µg lyophilized unit. Supports T cell survival assays, thymic development models, B lymphopoiesis, IL-7R/STAT5 signaling studies, and lymphocyte reconstitution experiments. Research use only.

Recombinant Mouse KGF (FGF7)

Recombinant Mouse KGF (FGF7) by Applied Biological Materials (ABM) is a tag-free, E. coli-expressed growth factor (19 kDa, ≥95% SDS-PAGE purity, &lt;1.0 EU/µg endotoxin, ED50 &lt;0.05 ng/mL), lyophilized from PBS — used for airway epithelial cell culture, lung organoid differentiation, and FGFR2-IIIb signaling research in murine systems. Available in 10 µg, 100 µg, and 1 mg formats.

Recombinant Mouse KGF (FGF7), 10 µg

Recombinant Mouse KGF (FGF7), 100 µg

Recombinant Mouse KGF (FGF7), 1.0 mg

Recombinant Mouse LIF

Z200485 by Applied Biological Materials (ABM) is a recombinant mouse LIF (Leukemia Inhibitory Factor) expressed in CHO cells, 20 kDa, tag-free, with greater than 95% purity by SDS-PAGE and endotoxin below 1.0 EU/µg. Bioactivity ED50 of 0.01 ng/mL in M1 myeloid differentiation assay.

Recombinant Mouse LIF by Applied Biological Materials is an E. coli-expressed, lyophilized leukemia inhibitory factor with 20 kDa molecular weight, &gt;95% purity by SDS-PAGE, endotoxin &lt;1.0 EU/µg (LAL), and ED50 ≤0.01 ng/mL in the M1 differentiation assay — used for mESC pluripotency maintenance, hematopoietic research, and cytokine signaling studies.