Recombinant Human LAMB4 Protein: Protocol & Usage Guide

Recombinant Human LAMB4 Protein is a recombinant form of the human laminin beta-4 subunit, produced for use in extracellular matrix research, cell adhesion assays, and related biomedical studies requiring a well-characterized, high-purity protein reagent.

Product Name

Recombinant Human LAMB4 Protein

SKU

rp366230

Protein Family

Laminin beta chain family (LAMB4 subunit)

Primary Application

Extracellular matrix research, cell adhesion and migration assays, protein interaction studies

Source Reference

absea #PP-1847

Recommended Storage

Follow supplier-specified storage conditions; avoid repeated freeze-thaw cycles

Background: LAMB4 and the Laminin Protein Family

Laminins are large heterotrimeric glycoproteins that form a major structural component of basement membranes throughout the body. Each laminin molecule is assembled from one alpha (α), one beta (β), and one gamma (γ) chain, giving rise to a diverse family of isoforms with tissue-specific expression patterns and distinct biological functions.

LAMB4 (Laminin Subunit Beta-4) encodes the beta-4 chain of laminin, one of the less extensively characterized members of the laminin beta chain subfamily. Beta chains contribute to the central long arm of the laminin cross-shaped structure and are essential for trimer assembly and integrin-mediated cell–matrix interactions. LAMB4 expression has been detected in a range of human tissues, and emerging research implicates laminin beta-4-containing isoforms in basement membrane integrity, cell signaling, and tissue homeostasis.

Recombinant Human LAMB4 Protein enables researchers to study the molecular roles of the LAMB4 subunit in isolation, to screen for binding partners, and to investigate its contribution to laminin heterotrimer assembly without the complexity of extracting native laminin from tissue sources.

Reconstitution and Preparation Protocol

Materials required: Sterile deionized water or the reconstitution buffer recommended in the product datasheet, sterile microcentrifuge tubes, micropipettes, and a vortex mixer or tube rotator.

1. Equilibrate to room temperature: Remove the vial from cold storage and allow it to equilibrate to room temperature for approximately 15–20 minutes before opening. This reduces condensation and prevents localized freezing during reconstitution.
2. Centrifuge the vial: Briefly centrifuge (approximately 5–10 seconds at low speed) to collect any lyophilized material from the walls and cap of the vial.
3. Add reconstitution buffer: Reconstitute the protein by adding the volume of sterile water or recommended buffer specified on the Certificate of Analysis (CoA) or product datasheet. Add the buffer gently along the wall of the vial to avoid foaming.
4. Dissolve gently: Do not vortex vigorously. Instead, gently swirl or pipette up and down until the protein is fully dissolved. Optionally, place on a tube rotator at 4 °C for 5–10 minutes.
5. Aliquot for storage: Prepare single-use aliquots to minimize freeze-thaw cycles. Transfer aliquots into sterile, low-binding microcentrifuge tubes and label clearly with date and concentration.

Note: Always refer to the specific product datasheet (absea #PP-1847) for protein concentration, recommended diluent, and any excipients included in the formulation, as these details supersede general guidance.

Recommended Assay Applications and Working Conditions

Recombinant Human LAMB4 Protein is suitable for a range of in vitro research applications. Typical uses include:

• ELISA and binding assays: LAMB4 can be coated onto microplate wells or used as a soluble analyte to study interactions with laminin-binding proteins, integrins, or antibodies. Optimize coating concentration empirically starting from the range suggested in the product datasheet.
• Western blot (WB): The recombinant protein can serve as a positive control for antibody validation and specificity testing. Load an appropriate amount per lane as specified in the CoA.
• Cell adhesion and migration assays: Substrate-coating with extracellular matrix proteins including laminin subunits may support the study of cell–matrix interactions. Empirical optimization of coating density is recommended.
• Protein–protein interaction studies (e.g., co-IP, SPR): LAMB4 can be used to investigate binding partners relevant to basement membrane assembly or disease-related pathways.

For all applications, use the protein at the concentration and buffer conditions indicated in the datasheet. Include appropriate positive and negative controls. Avoid sodium azide in buffers used in cell-based assays as it is cytotoxic.

Storage, Stability, and Handling Precautions

Storage: Store the lyophilized protein according to the conditions specified on the product label and datasheet. Lyophilized proteins are generally stable at –20 °C or –80 °C for extended periods. Reconstituted protein should be stored at 4 °C for short-term use (typically up to one week) or aliquoted and stored at –20 °C or –80 °C for longer-term use.

Avoid repeated freeze-thaw cycles: Each freeze-thaw event can lead to protein aggregation, loss of activity, and reduced assay performance. Single-use aliquots are strongly recommended.

Carrier protein addition: For dilute working solutions, addition of a carrier protein such as 0.1–0.5% bovine serum albumin (BSA) can help maintain protein stability and reduce adsorption to tube surfaces. Confirm compatibility with your specific assay before use.

General handling: Handle on ice when possible during preparation. Use low-binding polypropylene tubes. Wear appropriate personal protective equipment (PPE) in accordance with your institution's safety guidelines. Refer to the Safety Data Sheet (SDS) for hazard information.

Disclaimer: Specific stability data, shelf life, and exact storage temperatures must be confirmed from the official Aladdin Scientific product datasheet and CoA for SKU rp366230.

Quality Control and Troubleshooting

Quality control: Each lot of Recombinant Human LAMB4 Protein should be accompanied by a Certificate of Analysis (CoA) confirming identity, purity, and biological activity (where applicable). Verify the lot-specific CoA upon receipt. Check for expected molecular weight by SDS-PAGE or Western blot using a validated anti-LAMB4 antibody.

Common issues and solutions:

• Protein precipitation or aggregation: May occur if the protein is reconstituted incorrectly, stored improperly, or subjected to repeated freeze-thaw. Centrifuge the reconstituted solution briefly (e.g., 10,000 × g, 5 min, 4 °C) to pellet aggregates before use. If aggregation persists, review reconstitution buffer and concentration.
• Low signal in ELISA or binding assay: Optimize coating concentration and blocking conditions. Ensure the protein has not lost activity due to improper storage. Titrate the protein to determine the optimal working concentration.
• Non-specific bands on Western blot: Confirm antibody specificity and optimize blocking and antibody dilution conditions. Use the recombinant protein as a positive control to distinguish specific from non-specific signal.
• Reduced cell response in functional assays: Verify that the working buffer is compatible with cell culture conditions. Confirm the absence of cytotoxic additives such as sodium azide.

For technical support, contact Aladdin Scientific customer service with your lot number and CoA details.

Frequently asked questions

What is Recombinant Human LAMB4 Protein used for?

Recombinant Human LAMB4 Protein is used in extracellular matrix research to study the role of the laminin beta-4 subunit in basement membrane structure and cell–matrix interactions. Typical applications include ELISA, Western blot positive control, cell adhesion and migration assays, and protein–protein interaction studies.

How should Recombinant Human LAMB4 Protein be reconstituted?

Allow the vial to equilibrate to room temperature, briefly centrifuge to collect material, then add the volume of sterile water or recommended buffer specified in the Certificate of Analysis. Dissolve gently by swirling or slow rotation — avoid vigorous vortexing. Prepare single-use aliquots to prevent repeated freeze-thaw cycles.

How should I store Recombinant Human LAMB4 Protein to maintain its activity?

Store the lyophilized protein at –20 °C or –80 °C as specified on the product label. After reconstitution, use immediately or store short-term at 4 °C (up to approximately one week); for longer storage, aliquot and freeze at –20 °C or –80 °C. Avoid repeated freeze-thaw cycles, as these can cause aggregation and loss of activity.

What controls should I include when using LAMB4 protein in an assay?

Always include a positive control (e.g., a known amount of the recombinant protein detected with a validated anti-LAMB4 antibody) and a negative control (buffer or non-relevant protein) to confirm assay performance and antibody specificity. Lot-to-lot consistency should be monitored by running a reference standard in parallel.

Where can I find lot-specific quality information for SKU rp366230?

Lot-specific Certificate of Analysis (CoA) documents for SKU rp366230 are available through Aladdin Scientific. Contact customer service with your lot number or access the CoA through the Aladdin Scientific website product page for Recombinant Human LAMB4 Protein.

References

1. Aumailley M. The laminin family. Cell Adhesion & Migration. 2013;7(1):48-55. doi:10.4161/cam.22826
2. Hohenester E, Yurchenco PD. Laminins in basement membrane assembly. Cell Adhesion & Migration. 2013;7(1):56-63. doi:10.4161/cam.21831
3. absea Product Reference #PP-1847 — Recombinant Human LAMB4 Protein (internal supplier reference).

Products are supplied for research and development use only. Not for use in humans, animals, diagnosis, or therapy.