Recombinant Human Mer (also known as MERTK) is a valuable tool for research applications due to its well-characterized biological functions and versatility in experimental settings. Here are several reasons why you should consider using Recombinant Human Mer in your research:

1. Role in Key Biological Processes

• Apoptotic Cell Clearance: Mer is a receptor tyrosine kinase that plays a critical role in the phagocytic clearance of apoptotic cells by macrophages. This process is essential for tissue homeostasis and immune regulation.
• Immune Modulation: Mer signaling contributes to the polarization of macrophages toward an immunosuppressive M2-like phenotype, which is relevant in cancer, autoimmune diseases, and tissue repair.
• Retinal Function: In the retina, Mer regulates the phagocytosis of photoreceptor outer segments by the retinal pigment epithelium, making it important for vision research.

2. Applications in Disease Research

• Cancer: Mer is implicated in tumor progression, metastasis, and immune evasion. Inhibiting Mer signaling is a promising therapeutic strategy in oncology.
• Autoimmune and Inflammatory Diseases: Mer modulates innate immune responses and can influence the development of autoimmune conditions.
• Neurodegenerative Disorders: Mer's role in phagocytosis and immune regulation makes it relevant for studying neurodegenerative diseases where clearance of cellular debris is impaired.

3. Versatility in Experimental Techniques

• Protein Function Studies: Recombinant Mer can be used to study its interactions with ligands (such as Gas6 and Protein S), downstream signaling pathways, and functional outcomes in vitro and in vivo.
• Drug Screening and Target Validation: Recombinant Mer is useful in high-throughput screening assays to identify inhibitors or activators of Mer signaling, aiding in drug discovery.
• Structural Biology: High-purity recombinant Mer proteins are suitable for structural studies (e.g., X-ray crystallography, cryo-EM) to understand its molecular architecture and mechanism of action.

4. Diagnostic and Therapeutic Relevance

• Diagnostic Assays: Recombinant Mer can serve as an antigen or standard in ELISA and other immunoassays to detect Mer expression or activity in biological samples.
• Therapeutic Development: Understanding Mer's function and regulation can inform the development of targeted therapies, including monoclonal antibodies and small molecule inhibitors.

5. High Purity and Consistency

• Recombinant Mer proteins are produced with high purity and batch-to-batch consistency, ensuring reliable and reproducible results in your experiments.

6. Availability in Multiple Formats

• Recombinant Mer is available in various formats (e.g., Fc-tagged, His-tagged, GST-tagged), allowing flexibility in experimental design and downstream applications such as immunoprecipitation, Western blotting, and functional assays.

7. Support for Advanced Research Models

• Recombinant Mer can be used in 3D cell models, organoids, and stem cell research to study complex biological processes and disease mechanisms in a more physiologically relevant context.

In summary, Recombinant Human Mer is a powerful tool for investigating fundamental biological processes, disease mechanisms, and therapeutic strategies. Its availability in multiple formats and its well-defined roles in key cellular functions make it an excellent choice for a wide range of research applications.

You can use recombinant human Mer as a standard for quantification or calibration in your ELISA assays, provided it is appropriately validated for this purpose and matches the form of Mer detected by your assay.

Key considerations and best practices:

• Purity and Form: The recombinant protein should be highly purified and, ideally, match the native form (e.g., full-length extracellular domain, correct glycosylation, tag status) recognized by the ELISA antibodies. Carrier proteins like BSA may be included to enhance stability, but carrier-free forms are preferred if BSA interferes with your assay.
• Standard Curve Preparation: Prepare a standard curve using serial dilutions of the recombinant Mer in the same buffer or matrix as your samples to minimize matrix effects. Follow the reconstitution and dilution instructions specific to your recombinant protein lot.
• Validation—Parallelism and Linearity: Validate that the recombinant standard behaves similarly to endogenous Mer in your sample matrix. This is done by testing parallelism (serial dilutions of samples should run parallel to the standard curve) and dilution linearity (spiked recovery experiments). Differences in antibody affinity for recombinant versus endogenous Mer can affect quantification, so this validation is essential.
• Assignment of Value: The concentration assigned to your recombinant standard should ideally be determined by a validated method (e.g., amino acid analysis, HPLC) and, if possible, referenced to an international standard (such as NIBSC or WHO). If using a retail recombinant protein, do not rely solely on the mass stated on the vial; instead, value-assign the standard by measuring it in your ELISA.
• Lot-to-Lot Variability: Be aware that different lots of recombinant protein may show slight differences in immunoreactivity, affecting quantification. Always validate new lots for consistency.
• Documentation: Record all validation data, including standard curve performance, recovery, and parallelism, to ensure reproducibility and regulatory compliance.

Summary Table: Key Requirements for Using Recombinant Human Mer as an ELISA Standard

In conclusion:
Recombinant human Mer can be used as a standard for ELISA quantification if you rigorously validate its performance in your specific assay context and ensure it is immunologically equivalent to the endogenous analyte in your samples.

Recombinant Human Mer (MERTK) protein has been validated for several applications in published research, primarily focusing on its role in cellular signaling, phagocytosis, and immune regulation. Key applications include:

1. Blocking Assays: Recombinant Mer protein is used to block MerTK-mediated signaling pathways, allowing researchers to study the functional consequences of MerTK inhibition in various cell types, including microglia and macrophages.

2. Kinase Assays: The recombinant protein is validated for use in kinase activity assays, enabling the study of MerTK enzymatic function and downstream signaling events.

3. Phagocytosis Studies: MerTK is a key mediator of non-inflammatory, homeostatic phagocytosis. Recombinant Mer protein is used to investigate the uptake of cellular debris and pathological proteins, such as alpha-synuclein fibrils, by microglia and macrophages.

4. Immune Regulation: MerTK signaling is involved in the regulation of immune responses, including the inhibition of Toll-like receptor (TLR)-mediated innate immunity and the promotion of immunosuppressive M2-like macrophage polarization.

5. Cell and Tissue Culture: Recombinant Mer protein is used in cell culture systems to study MerTK-dependent processes, such as apoptotic cell clearance and platelet aggregation.

6. ELISA Standards: The protein can serve as a standard in ELISA assays to quantify MerTK expression or activity in biological samples.

7. Pull-down and Binding Assays: Recombinant Mer extracellular domain (often as a fusion protein with Fc) is used in pull-down assays to study interactions with ligands such as Gas6 and Protein S.

8. Therapeutic Target Validation: The protein is used in preclinical studies to validate MerTK as a therapeutic target in diseases such as Parkinson’s disease, cancer, and retinal degeneration.

These applications highlight the versatility of recombinant Human Mer protein in both basic research and translational studies.

Reconstitution and Preparation of Recombinant Human Mer Protein for Cell Culture Experiments

General Reconstitution Principles

Reconstituting lyophilized recombinant proteins requires careful attention to technique and conditions to maintain protein integrity and functionality. The fundamental approach involves rehydrating the lyophilized powder with an appropriate buffer solution while minimizing protein aggregation and denaturation.

Step-by-Step Reconstitution Protocol

Pre-reconstitution preparation:

Before opening the vial, briefly centrifuge or tap down the lyophilized protein to consolidate any powder that may have adhered to the tube walls or cap during storage and shipping. Allow both the vial and your reconstitution buffer to equilibrate to room temperature before mixing to minimize thermal stress on the protein.

Buffer selection and reconstitution:

Reconstitute the protein to a final concentration of 0.1 to 1.0 mg/mL, which represents the optimal range for most recombinant proteins. For example, if you have 100 µg of protein, calculate the appropriate volume of reconstitution buffer needed to achieve your target concentration. Sterile, distilled water is acceptable for initial reconstitution, though you may consider using a buffer containing carrier proteins such as 0.1% bovine serum albumin (BSA), 10% fetal bovine serum (FBS), or 5% human serum albumin (HSA) to enhance protein stability.

Mixing technique:

Add the reconstitution buffer slowly to the vial and allow the protein to dissolve gently. Do not vortex the sample, as vigorous mixing can promote protein aggregation and denaturation. Instead, gently pipette or swirl the solution until the protein is completely solubilized.

Storage Considerations

For long-term storage, dilute the reconstituted protein with a carrier protein-containing solution and add glycerol to a final concentration of 5-50% to provide cryoprotection. Aliquot the reconstituted protein into smaller portions to minimize freeze-thaw cycles, which can compromise protein stability. Store aliquots at -20°C in a conventional freezer or at -80°C in an ultra-low temperature freezer for extended preservation.

Cell Culture Application Notes

When preparing the protein for cell culture experiments, ensure that your reconstitution buffer is compatible with your specific experimental conditions. The carrier proteins and cryoprotectants you select should not interfere with your downstream assays or cellular interactions. If the Mer protein will be used in direct cell culture applications, verify that any additives are appropriate for your cell type and experimental design.