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LONG® R3 IGF-I Cell Culture Supplement

LONG®R3 IGF-I (LONG R3) is 200 times more potent and two times more stable in cell culture than insulin. SAFC® is the exclusive worldwide distributor of LONG®RIGF-I for industrial cell culture applications.

potent cell culture supplement

LONG®R3 IGF-I is a critically important mitogenic growth factor often used in mammalian cell culture to increase yield significantly.  Such growth factors are fundamental supplements to chemically-defined media.  LONG®R3 IGF-I is a recombinant analog of human insulin-like growth factor-I (IGF-I) that has been specifically engineered for the enhancement of cell culture performance.

  • More biologically potent in vitro than either insulin or native IGF-I
  • Increases recombinant protein production significantly
  • Ideal for both research and large-scale culture systems utilizing serum-free or low-level serum applications

LONG®RIGF-I is compatible with multiple cell types.  Any mammalian cell type that responds to insulin in cell culture has the potential to respond to LONG®RIGF-I.

long-product-image.jpgRepligen works collaboratively and exclusively with SAFC® for the worldwide distribution of LONG®R3  IGF-I in industrial cell culture applications.


better than insulin

200 times more potent and 2 times more stable in cell culture than insulin


Enables more streamlined cell culture feeding strategies with increased cell density, higher viability and extended culture duration


Dry or liquid format, use with multiple cell types


Helps ensure regulatory acceptance through an animal-free manufacturing process 

Secure supply

Mitigates risk through inventory backed by comprehensive supply chain risk management


Reduces cold chain shipping and storage costs since LONG®R3 IGF-I ships at ambient conditions and stored at 2-8°C

Repligen在ISO 9001质量管理体系下开发和生产用于生物制药行业的产品。我们专注于及时交付高质量、一致且稳健的产品,以确保我们客户的业务连续性。


Cell compatibility, Formats and Sizes

LONG®RIGF-I is compatible with multiple cell types.  Any mammalian cell type that responds to insulin in cell culture has the potential to respond to LONG®RIGF-I.

  • CHO clones
  • HEK 293
  • Vero
  • MDCK
  • Fibroblasts

LONG®RIGF-I is available in two formats, both stable at 2-8°C.  LONG®RIGF-I can also be milled into cell culture media for additional flexibility and convenience.

Freeze-dried powder

  • 5 mg (sample size*)
  • 50 mg

Ready to use liquid

  • 5 mL (sample size*)
  • 100 mL 
  • 250 mL 
  • 500 mL 
  • 1L (1000 mL)

*Sample size is not fully validated. The material is filled from validated intermediate material. Stability information is inferred from the stability trials for 100mL and 50mg respectively.

Optimizing Cell Culture

Cell culture supplements are essential for long-term growth and productivity of cell lines in serum-free media formulations. Both insulin and LONG®R3 IGF-I, a more potent supplement that directly targets and activates the IGF-I receptor, are employed by the biopharmaceutical industry today to support the growth of recombinant cell lines. This webinar will show how these two supplements, used separately and in combination, impact viable cell density and IgG production of multiple CHO cell lines.  It will demonstrate how a combination of LONG®R3 IGF-I and insulin results in less protein supplementation and, therefore, less potential impact on downstream processing. 

better science for better cell culture

LONG® technology consists of a fusion of the growth factor with a portion of growth hormone sequence. The fusion improves growth factor production without imparting its biological activity. 

A distinct biological advantage
All mammalian cells secrete IGF Binding Proteins (IGFBPs) which bind to and inhibit native IGF-I. The substitution of an arginine for glutamic acid at position three in LONG®RIGF-I, in conjunction with the 13 amino acid N-terminal extension peptide, results in > 1000 fold reduced affinity for IGFBPs, enhancing its bio-availability and effectiveness in comparison to native IGF-I.

Specificity is the key to increased productivity
Unlike insulin, LONG®RIGF-I specifically targets and activates the type I IGF Receptor (IGF-IR) resulting in greater activation of downstream signaling cascades responsible for proliferation and inhibiting apoptosis. Greater activation of these key pathways results in increased cell density, higher viability and extended cell culture productivity.

To learn more about the use of LONG®R3 IGF-I in stem cell and cell therapy applications, please contact Repligen.


reliable performance

LONG®R3 IGF-I has been shown to improve volumetric productivity in CHO cell culture by up to 62% over cell culture with no supplementation and 40% over cell culture supplemented with insulin.


Secure Supply Chain

LONG®RIGF-I is backed by one of the most comprehensive risk mitigation strategies for any cell culture raw material. Repligen manages a global inventory safety stock of over 2 years forecasted demand. This inventory, together with multi-site manufacturing capability, ensures an uninterrupted supply to customers.

Repligen develops and manufactures products for the biopharmaceutical industry under an ISO 9001 quality management system.  We focus on the timely delivery of high quality, consistent and robust products, and ensuring business continuity for our customers.


Secure Supply Chain


LONG® R3 IGF-I ELISA试剂盒是目前唯一一款用于LONG® R3 IGF-I定量检测的商品化试剂盒。这种三明治式ELISA试剂盒使用生物素化二级抗体和链霉亲和素-HRP进行检测,可快速、准确、简便地用于细胞培养和药用底物样品。

  • 对天然或重组IGF-1有限的反应性
  • 对胰岛素无反应性
  • 即用型ELISA板,可允许立即进行分析,而不需要额外的包板及封闭步骤


  • LONG® R3 IGF-I 包被的洗脱板,96孔
  • LONG® R3  IGF-I 标准品
  • 稀释液
  • 生物素化检测抗体
  • 链霉亲和素过氧化物酶
  • TMB过氧化物酶底物
  • LoBind® 1.5mL EP管

performance summary

LONG<sup>®</sup> R3 IGF-I ELISA 试剂盒

LONG®R3 IGF-I is not approved or permitted for use in any human application. Repligen provides LONG®R3 IGF-I only to qualified customers expressly for use in cell culture supplementation or for other research purposes.

SAFC®为Merck KGaA注册商标。