Recombinant Rat ICAM-1

Recombinant Rat ICAM-1 is used in research applications to model and investigate immune cell adhesion, inflammation, and vascular biology in rat systems, enabling precise mechanistic studies and translational relevance for rodent models.

ICAM-1 (Intercellular Adhesion Molecule 1) is a key cell-surface glycoprotein involved in leukocyte adhesion and transmigration, acting as a ligand for integrins such as LFA-1 and Mac-1 on immune cells. Its expression is upregulated during inflammation and is critical for recruiting immune cells to sites of tissue injury or infection, making it a central molecule in studies of immune response, vascular dysfunction, and inflammatory diseases.

Scientific applications for recombinant rat ICAM-1 include:

• Cell adhesion assays: Recombinant ICAM-1 can be coated on surfaces to study the binding and migration of rat leukocytes, such as neutrophils and lymphocytes, under controlled conditions.
• Signal transduction studies: ICAM-1 engagement triggers intracellular signaling pathways associated with inflammation, which can be dissected using recombinant protein in vitro.
• Drug screening and mechanistic studies: Recombinant ICAM-1 is used to evaluate inhibitors or antibodies targeting adhesion processes, relevant for anti-inflammatory or immunomodulatory drug development.
• Modeling vascular dysfunction: ICAM-1 is a marker of endothelial activation and dysfunction, and recombinant protein enables studies on vascular pathology in rat models, including transplantation, ischemia-reperfusion injury, and gestational vascular disorders.
• Preclinical validation: Using rat ICAM-1 ensures species-specific interactions, which is essential for translational studies in rodent models before moving to clinical research.

Best practices:

• Use recombinant rat ICAM-1 in cell-based assays, ELISA standards, or as a substrate for adhesion studies to ensure reproducibility and species compatibility.
• Select carrier-free or BSA-containing formulations depending on downstream application (e.g., cell culture vs. biochemical assays).

Summary of advantages:

• Enables mechanistic dissection of immune cell trafficking and inflammation in rat models.
• Facilitates drug screening and validation of targeted delivery systems.
• Provides species-specific reagents for translational research bridging in vitro and in vivo studies.

Using recombinant rat ICAM-1 is essential for accurate modeling of immune and vascular processes in rat-based research, supporting both basic science and preclinical therapeutic development.

Yes, recombinant Rat ICAM-1 can be used as a standard for quantification or calibration in ELISA assays, provided it is properly characterized and compatible with your assay system.

Supporting details:

• ELISA quantification relies on a standard curve generated using known concentrations of the target protein, typically recombinant ICAM-1 in this case. The recombinant standard should match the epitope recognized by the assay antibodies and be of high purity.
• Multiple commercial rat ICAM-1 ELISA kits use recombinant rat ICAM-1 as the standard for calibration, demonstrating its suitability for quantitative assays. For example, the immunogen description for one kit specifies that the standard is recombinant rat ICAM-1/CD54, amino acids 28-493, expressed and purified from a recombinant system.
• When using recombinant ICAM-1 as a standard, ensure it is prepared in the same buffer/matrix as your samples to minimize matrix effects and optimize recovery. Some kits recommend evaluating diluents for complex matrices such as serum or plasma.
• The recombinant protein should be carrier-free or contain only compatible additives (e.g., BSA) depending on your assay requirements. Carrier proteins can affect assay sensitivity or background.
• Always validate the standard curve for linearity, accuracy, and reproducibility within your assay range. Use appropriate curve fitting (e.g., 4-PL or 5-PL) for best quantification.

Best practices:

• Confirm the recombinant ICAM-1 sequence and post-translational modifications are representative of the native protein in your samples.
• Prepare serial dilutions of the recombinant standard according to your assay protocol, covering the expected concentration range of your samples.
• Include quality controls and, if possible, compare the recombinant standard to a native protein standard for cross-validation.

In summary, recombinant Rat ICAM-1 is widely accepted and routinely used as a standard for ELISA quantification, provided it is appropriately validated for your specific assay system.

Recombinant Rat ICAM-1 has been validated for several key applications in published research, primarily in studies of inflammation, immune cell adhesion, and drug delivery systems.

Validated Applications:

• Cellular and Molecular Assays:
  Recombinant rat ICAM-1 is widely used in in vitro assays to study leukocyte adhesion, transmigration, and signaling pathways associated with inflammation and endothelial dysfunction. It serves as a ligand in cell adhesion assays to investigate interactions between immune cells and endothelial cells.

• Stem Cell Migration and Tissue Repair:
  ICAM-1 has been used to study stem cell migration and tissue repair mechanisms, such as in models of calvarial defect repair in rats, where its expression and modulation (e.g., by microRNA-221) influence endogenous stem cell migration.

• Immunohistochemistry (IHC) and Western Blot:
  Antibodies against rat ICAM-1, often validated using recombinant protein, are employed in IHC to detect ICAM-1 expression in rat tissues, including brain and kidney, and in Western blot for protein quantification in tissue homogenates.

• Exosome and Immune Suppression Studies:
  Recombinant ICAM-1 is used to model and analyze the role of ICAM-1 in exosome-mediated immune suppression, particularly in the interaction between exosomal PD-L1 and T cell PD-1, both in vitro and in vivo.

• Drug Delivery and Targeting:
  Recombinant rat ICAM-1 has been validated as a target for drug delivery systems (DDS), including nanoparticle formulations. It is used to develop and test cellular models for targeted delivery via CAM-mediated endocytosis, supporting preclinical studies on pharmacokinetics, biodistribution, and therapeutic efficacy in rodent models.

• ELISA Standard:
  Recombinant rat ICAM-1 is used as a standard in ELISA assays for the quantitative determination of soluble ICAM-1 in culture supernatants, cell lysates, and biological fluids.

Additional Context:

• ICAM-1 is essential for leukocyte transmigration and is a marker of endothelial dysfunction, making it a critical molecule in studies of vascular inflammation and immune cell trafficking.
• Recombinant ICAM-1 is also used in mechanistic studies of cancer metastasis, particularly in models investigating tumor cell adhesion and cluster formation.
• Its utility in developing recombinant cell lines expressing ICAM-1 from various species supports cross-species comparisons and pharmaceutical translation.

Summary Table of Validated Applications

These applications are supported by published research and demonstrate the versatility of recombinant rat ICAM-1 in immunology, cell biology, and translational medicine.

To reconstitute and prepare Recombinant Rat ICAM-1 protein for cell culture experiments, dissolve the lyophilized protein in sterile water or buffer (commonly PBS) to the desired concentration, ensuring gentle mixing and avoiding vigorous agitation to prevent protein denaturation. Use aseptic technique throughout to maintain sterility.

Step-by-step protocol:

• Preparation:

  • Allow the vial to equilibrate to room temperature before opening to minimize condensation.
  • Confirm the recommended diluent from the product datasheet; most recombinant ICAM-1 proteins are lyophilized from PBS and can be reconstituted in sterile water or PBS (pH 7.2–7.3, without calcium or magnesium).
  • If the protein contains stabilizers (e.g., trehalose, mannitol), these do not interfere with cell culture applications.

• Reconstitution:

  • Add sterile water or PBS to the vial to achieve the desired stock concentration (e.g., 100 µg/mL or higher for initial stock).
  • Gently mix by inverting or slow pipetting; avoid vortexing or vigorous shaking to prevent foaming and protein aggregation.
  • Allow the solution to sit at room temperature for 15–30 minutes to ensure complete dissolution.
  • If necessary, centrifuge briefly at low speed to remove bubbles.

• Sterility and Storage:

  • Use aseptic technique throughout preparation.
  • After reconstitution, aliquot the solution to avoid repeated freeze-thaw cycles.
  • Store aliquots at 2–8 °C for up to one month, or at –20 °C to –70 °C for longer-term storage.
  • Avoid repeated freeze-thaw cycles, which can degrade the protein.

• Preparation for Cell Culture:

  • Dilute the stock solution in cell culture medium or buffer immediately before use to the working concentration required for your experiment (e.g., for coating plates or direct addition to cells).
  • For plate coating, typical concentrations range from 5–20 µg/mL in PBS; incubate plates at 4 °C overnight or at room temperature for 1–2 hours, then wash with PBS before adding cells.
  • For soluble applications, add directly to cell culture medium at the desired final concentration.

Additional notes:

• Always consult the specific product datasheet for lot-specific instructions and recommended concentrations.
• If the protein is fused to an Fc tag or other domains, confirm compatibility with your assay or cell type.
• Endotoxin levels are typically low (<0.1 EU/µg), but verify if your application is sensitive to endotoxin.

This protocol ensures optimal solubility, activity, and sterility of recombinant rat ICAM-1 for cell culture experiments.