Cell Culture

<h2 data-section-id="pdko8n" data-start="0" data-end="50">What are recombinant proteins for cell culture?</h2>
&nbsp;
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.
&nbsp;
<h2 dir="ltr">What you will find:</h2>
&nbsp;
<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>
&nbsp;
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>
&nbsp;
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 Rat IL6

Recombinant Rat IL-6 by Applied Biological Materials is expressed in E. coli with purity >95% by SDS-PAGE, endotoxin <1.0 EU/µg by LAL, ED50 20–40 ng/mL in monkey 4MBr-5 proliferation assay, and tag-free lyophilized formulation in PBS.

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 Rat IL6, 10 µg

Recombinant Rat IL6, 1.0 mg

Flyer

Brochure

Recombinant Rat LIX  (CXCL5)

Recombinant Rat LIX (CXCL5) — catalog number Z300125 by Applied Biological Materials — is a tag-free, E. coli-expressed neutrophil-activating chemokine with 11 kDa molecular weight, greater than 95% purity by SDS-PAGE, endotoxin below 1.0 EU/µg by LAL, and an ED50 of 2.0–40.0 ng/mL for neutrophil chemoattraction. The lyophilized protein (UniProt P97885) is formulated in phosphate buffer with 100 mM NaCl at pH 7.5 and is used in CXCR2 signaling, neutrophil migration assays, and in vitro inflammatory models. Available from MBP in 20 µg and 1.0 mg sizes — order via <a href="https://www.mbpinc.net/quickorder">Quick Order</a> or email <a href="mailto:customerservice@mbpinc.net">customerservice@mbpinc.net</a>.

Recombinant Rat LIX  (CXCL5), 20 µg

Recombinant Rat LIX (CXCL5), 1.0 mg

Recombinant Rat TNF

Recombinant Rat TNF — Z300065 by Applied Biological Materials. E. coli-expressed, tag-free, &gt;95% pure by SDS-PAGE, 17 kDa, 157 aa, endotoxin &lt;1.0 EU/µg. ED50 20–40 ng/mL. Available in 20 µg, 100 µg, and 1.0 mg.

Recombinant Rat TNF, 20 µg

Recombinant Rat TNF, 100 µg

Recombinant Rat TNF, 1.0 mg

<h2 data-section-id="6b0hnw" data-start="102" data-end="151">What are SV40T antigen overexpression viruses?</h2>
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SV40T antigen overexpression viruses are recombinant lentiviral particles carrying the simian virus 40 (SV40) large T antigen gene, a hexamer protein that inactivates the p53 and retinoblastoma (Rb) tumor suppressor pathways, bypassing the senescence checkpoints that normally limit primary cell proliferation. Some constructs deliver the large T antigen alone, while others include both large and small T antigens. Related entities include p53/Rb pathway inactivation, broad cross-species immortalization (human, mouse, rat, bovine, porcine, canine), karyotype/tumorigenicity characterization (soft agar assay), and antibiotic/fluorescent selection markers.
&nbsp;
<h2 dir="ltr">What you will find:</h2>
&nbsp;
<ul>
<li dir="ltr" role="presentation">Lenti-SV40 (tsA58 Mutant) for cell proliferation with inducible control and temperature-sensitive expression</li>
<li dir="ltr" role="presentation">Lenti-SV40T (Puro/Neo/No Marker) provides stable integration with versatile selection markers of highly concentrated lentiviral stocks&nbsp;</li>
<li dir="ltr" role="presentation">Adeno-SV40 Adenovirus for transient T-antigen expression with high-efficiency adenoviral vectors</li>
<li dir="ltr" role="presentation">Retro-SV40 &amp; Retro-SV40LT for special integration in proliferating cells.</li>
<li dir="ltr" role="presentation">Lenti-SV40Tt Lentivirus: Small T and Large T antigens for improved transformation.</li>
</ul>
&nbsp;
<h2 data-section-id="ykynp3" data-start="1032" data-end="1092">How to choose SV40T antigen overexpression virus products</h2>
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Large T antigen alone vs. large and small T antigen
Constructs delivering large T antigen alone target p53/Rb pathway inactivation specifically, while large-and-small-T constructs include additional SV40 small T antigen activity affecting protein phosphatase 2A (PP2A) signaling; confirm which form a published protocol specifies, since the two can produce different immortalization efficiencies and phenotypes.
Species applicability
SV40 large T antigen has documented immortalization success across human, mouse, rat, bovine, porcine, and canine primary cells, making it a broadly applicable option when hTERT (human-specific) is not suitable for the target species.
Selection marker and promoter
As with TERT lentivirus, SV40T constructs are available under CMV or EF1-alpha promoters with antibiotic resistance (puromycin, hygromycin, blasticidin, neomycin/G418, zeocin) or fluorescent-antibiotic fusion markers (GFP-Bsd, RFP-Puro); select based on the target cell line's existing markers and expected culture duration.
Post-immortalization characterization
Because SV40 large T antigen inactivates tumor suppressor pathways, immortalized lines should be characterized for karyotype changes and tested by assays such as soft agar colony formation and tumorigenicity testing if downstream applications require confirmation that the line has not undergone malignant transformation.
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<h2 data-section-id="1fljvas" data-start="3482" data-end="3507">Specifications context</h2>
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SV40T antigen lentivirus is typically supplied at titers around 1x10^8 TU/mL, shipped on dry ice and stored at -80&deg;C, with constructs validated by full-length sequencing and confirmed free of common contaminants. Immortalized lines derived from SV40T transduction are commonly characterized by Western blot or immunofluorescence confirming SV40-LT protein expression, alongside marker expression comparison to the original primary cells. As of 2026, SV40 large T antigen remains the most broadly cross-species-applicable immortalization approach, often selected when hTERT (human-specific) is not an option for the target species or when faster immortalization is prioritized over preserving the original phenotype.
This sub-category sits within MBP's cell immortalization catalog alongside TERT overexpression viruses and additional immortalization agents. Labs constructing custom SV40T expression vectors can also review MBP's cloning reagents. MBP's specialist team can help confirm species applicability and vector format for a specific primary cell type before order placement.
<a href="https://mbpinc.net/contact-us">Contact the expert team </a>at MBP today to get high-quality SV40T antigen overexpression viruses.

SV40T Antigen Overexpression Viruses

Lentiviral Vector Amplification - Protocol

Lentivector Packaging - Protocol

Lentivirus Infection - Protocol

Cell Immortalization - Handbook

Cell Immortalization Reagents - FAQ

Retro-SV40 Retrovirus

Unit Quantity

Description

Application

Expression System Type

Vector Map

Note

Caution

Retro-SV40LT Retrovirus

Unpacking and Storage Instructions

<h2 data-section-id="3d1466" data-start="0" data-end="47">What are cell culture buffers and solutions?</h2>
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Cell culture buffers and balanced salt solutions are isotonic solutions used to wash, dilute, transport, and temporarily maintain cells outside of complete growth media. Unlike culture media, these solutions do not contain the nutrients and growth factors required for cell proliferation. Instead, their primary role is to maintain physiological pH and osmotic balance while protecting cells from stress during handling and experimental procedures.
The most commonly used cell culture buffers include PBS (Phosphate-Buffered Saline), DPBS (Dulbecco's Phosphate-Buffered Saline), HBSS (Hank's Balanced Salt Solution), and EBSS (Earle's Balanced Salt Solution). These solutions are widely used in cell washing, passaging, tissue dissociation, sample preparation, immunoassays, and short-term cell maintenance.
&nbsp;
<h2 dir="ltr">What you will find:</h2>
&nbsp;
<ul>
<li dir="ltr" role="presentation">Standard Isotonic Buffers to wash cells, maintain osmotic balance, and dilute reagents.</li>
<li dir="ltr" role="presentation">Biological Buffering Agents for metabolic support and pH maintenance.</li>
<li dir="ltr" role="presentation">Cell Dissociation &amp; Neutralizing Reagents maintain high cell viability and are used for cell recovery, detachment, and passaging</li>
<li dir="ltr" role="presentation">Surface Coating &amp; Matrix Solutions with high-grade gelatin for improved cell attachment.</li>
<li dir="ltr" role="presentation">Insulin-Transferrin-Selenite (ITS), Bovine Serum Albumin (BSA), and high-purity Holo-Transferrin for enhanced cell growth and viability</li>
</ul>
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<h2 data-section-id="1cuz7jf" data-start="1165" data-end="1216">How to choose cell culture buffers and solutions</h2>
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PBS vs. DPBS PBS is a simple sodium chloride/phosphate buffer solution. DPBS adds potassium chloride and may include calcium, magnesium, glucose, and pyruvate depending on formulation. The practical difference between PBS and DPBS formulations is minimal &mdash; both maintain pH 7.2-7.4 and osmolality ~280-315 mOsm/kg and are functionally interchangeable for standard washing, immunoassay, and sample preparation applications. If your protocol is sensitive to minor salt concentration differences, compare specific formulation sheets rather than assuming equivalence. &nbsp; Calcium/magnesium-free vs. calcium/magnesium-containing Calcium and magnesium facilitate cell-cell and cell-surface adhesion. Calcium/magnesium-free PBS, DPBS, or HBSS is required: before enzymatic dissociation (residual Ca/Mg inhibits trypsin, requiring more enzyme and harsher conditions &mdash; the most common cause of poor trypsinization results), for rinsing EDTA or other chelators from culture, and for minimizing cell-cell aggregation during gentle dissociation or suspension recovery. Calcium/magnesium-containing formulations support cell binding and clumping, useful for transport applications or attachment-dependent procedures. &nbsp; HBSS/EBSS vs. PBS/DPBS for short-term maintenance HBSS and EBSS include sodium bicarbonate buffering and may include glucose, providing meaningfully better short-term physiological support for cells &mdash; particularly under CO₂ atmosphere &mdash; than the simpler PBS/DPBS formulations. Use HBSS/EBSS when cells need to remain viable for a meaningful period outside complete growth media (tissue dissociation workflows, transport, short-term holding). Use PBS/DPBS for washing steps, immunoassay/Western blot dilutions, and sample preparation where osmotic balance &mdash; not metabolic support &mdash; is the requirement. &nbsp; Phenol red and glucose/pyruvate variants DPBS and HBSS are available with or without phenol red and with or without glucose/pyruvate, allowing matching to downstream applications (phenol red-free for fluorescence work; glucose/pyruvate-containing for short-term metabolic support). &nbsp; Endotoxin and quality testing Regular quality testing of balanced salt solutions includes osmolality, pH, stability, and screening for endotoxins and bacterial/fungal contamination. For immune cell handling and other endotoxin-sensitive applications, premium formulations document endotoxin levels below 0.005 EU/mL &mdash; a meaningfully tighter specification than standard research-grade buffers. &nbsp; Powder vs. liquid format Powdered balanced salt solutions are manufactured without sodium (to avoid sodium bicarbonate off-gassing during storage), requiring sodium bicarbonate addition, pH adjustment, and sterile filtration at time of preparation &mdash; following the same principle as powdered classic media.Specifications context
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<h2>Specifications context</h2>
&nbsp;
Most balanced salt solutions are formulated to maintain physiological conditions with a pH of approximately 7.2&ndash;7.4 and osmolality ranging from about 280&ndash;315 mOsm/kg. These properties help minimize osmotic stress and maintain cell viability during handling.
Calcium- and magnesium-free DPBS remains one of the most commonly specified buffers for cell dissociation workflows because it improves the effectiveness of trypsin and other detachment enzymes. HBSS and EBSS continue to be widely used when short-term metabolic support is required outside complete growth media.
<a href="https://mbpinc.net/contact-us">Contact the expert team</a> at MBP today to get high-purity buffers and solutions for your lab.

Buffers & Solutions

Buffers/Salts

SB216763

Shipping condition

<h2 data-section-id="1h8mvlk" data-start="0" data-end="45">What are primary cell culture medium kits?</h2>
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Primary cell culture medium kits are complete, ready-to-prepare culture systems that combine a cell-type-specific basal medium with the supplements required for optimal growth and maintenance of primary cells. Unlike purchasing media, serum, growth factors, and antibiotics separately, these kits provide all components in validated proportions, ensuring that the medium performs as intended for a specific primary cell type.
A typical kit includes a basal medium, a cell-specific growth supplement, an antibiotic component where appropriate, and fetal bovine serum (FBS) or an equivalent supplement when required. The components are designed to be combined directly according to the manufacturer's instructions, reducing preparation errors and improving consistency between experiments.
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<h2 data-path-to-node="5">What you will find:</h2>
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<ul data-path-to-node="6">
<li style="font-family: arial, helvetica, sans-serif;">
Tissue-specific primary cell culture medium kits
</li>
<li style="font-family: arial, helvetica, sans-serif;">
Specialized growth media for endothelial and epithelial cells
</li>
<li style="font-family: arial, helvetica, sans-serif;">
Workflow systems for thawing, plating, and maintenance of hepatocytes&nbsp;
</li>
<li style="font-family: arial, helvetica, sans-serif;">
Differentiation media for progenitor and stem cells&nbsp;
</li>
<li style="font-family: arial, helvetica, sans-serif;">
Serum-free bioprocessing and cryopreservation reagents
</li>
<li style="font-family: arial, helvetica, sans-serif;">
Targeted fibroblast, smooth muscle, and myocyte growth kits
</li>
</ul>
&nbsp;
<h2 data-section-id="1nip7jz" data-start="1066" data-end="1116">How to choose a primary cell culture medium kit</h2>
&nbsp;
Match the kit to the cell type
Primary cells have highly specialized nutritional and signaling requirements. Kits are available for endothelial cells, hepatocytes, astrocytes, epithelial cells, fibroblasts, stem cells, and many other cell types. Selecting a kit specifically designed for the target cell type is essential for maintaining normal cellular function and morphology.
Serum-containing vs. serum-free formulations
Traditional kits often include FBS as a source of growth factors and nutrients. Serum-free and xeno-free kits replace animal-derived components with defined supplements, reducing variability and supporting applications that require animal-component-free culture conditions.
Complete kit convenience
Most kits provide all major components needed to prepare complete culture medium. This eliminates the need to source multiple reagents individually and helps ensure that supplements are used at the correct concentrations.
Antibiotic inclusion
Many primary cell culture kits include antibiotics to reduce contamination risk during routine culture. However, some specialized formulations, particularly those designed for immune cells and mononuclear cells, are intentionally supplied without antibiotics because these additives can influence cellular responses and experimental outcomes.
Storage and preparation
Kit components are typically stored separately until needed. Basal media and supplements are usually refrigerated, while serum components may require frozen storage before use. Once mixed into complete medium, shelf life is generally shorter than that of the individual components, making it advisable to prepare only the amount needed for near-term use.
Specialized differentiation systems
Some kits are designed not only for maintenance but also for cellular differentiation. These systems may include multiple supplements added sequentially throughout a protocol to guide stem cells or progenitor cells through defined developmental stages.
<h2 data-section-id="dydsco" data-start="3131" data-end="3173">&nbsp;</h2>
<h2 data-section-id="1fljvas" data-start="4061" data-end="4086">Specifications context</h2>
&nbsp;
Primary cell culture medium kits are commonly supplied in a format consisting of a basal medium bottle accompanied by concentrated supplements and serum components that are added directly before use. This approach simplifies preparation while ensuring that all components have been optimized and tested together.
<a href="https://mbpinc.net/contact-us" title="Contact the expert team at MBP">Contact the expert team at MBP</a> today and get optimized primary cell culture medium kits for your lab.

Primary Cell Culture Medium kits

Serum Free Cryopreservation Medium

Serum Free Cryopreservation Medium TM026 by ABM: 25 ml serum-free formulation for mammalian cell cryopreservation and biobanking. Lot-tested for sterility, pH, osmolality, and endotoxin. Store at 4–8°C. Research use only.