Recombinant Human CDH8 Protein: Handling & Usage Protocol

Recombinant Human CDH8 Protein is a research-grade recombinant cadherin family member produced for use in cell adhesion studies, neurodevelopmental research, and related in vitro assays requiring high-purity, biologically active protein.

Product Name

Recombinant Human CDH8 Protein

SKU

rp369141

Protein Family

Cadherin (Type II classical cadherin)

Species Origin

Human (Homo sapiens)

Primary Application

Cell adhesion assays, neuroscience research, protein interaction studies

Storage Recommendation

Store at -80 °C upon receipt; avoid repeated freeze-thaw cycles

Background: CDH8 and Its Biological Role

CDH8, also known as Cadherin-8, is a member of the Type II classical cadherin subfamily of calcium-dependent cell adhesion molecules. Cadherins mediate homophilic cell–cell adhesion through their extracellular cadherin (EC) repeat domains, and CDH8 is predominantly expressed in the nervous system, particularly during brain development. It plays important roles in neuronal migration, axon guidance, synapse formation, and the establishment of neural circuits.

The extracellular domain of CDH8 contains five EC repeats that bind calcium ions to maintain a rigid, elongated conformation required for trans-dimerization between opposing cell membranes. Loss-of-function variants in CDH8 have been associated with neurodevelopmental disorders, including autism spectrum disorder (ASD), making it a relevant target for research into synaptic biology and neurological disease mechanisms.

Reconstitution and Buffer Preparation

Recombinant Human CDH8 Protein (rp369141) is typically supplied as a lyophilized powder or liquid formulation. Follow the specific reconstitution instructions provided on the product datasheet, as formulation details may vary by lot. The general recommended procedure is outlined below:

1. Centrifuge the vial briefly (1,000–2,000 × g, 30 seconds) before opening to collect lyophilized material at the bottom of the tube.
2. Reconstitute in sterile, deionized water or an appropriate buffer (e.g., PBS, pH 7.4) to yield a stock concentration typically between 0.1–1.0 mg/mL. For calcium-dependent activity, supplement the buffer with 1–5 mM CaCl₂.
3. Gently pipette up and down to dissolve; avoid vortexing, which can denature the protein and disrupt cadherin domain integrity.
4. Allow equilibration at room temperature for 5–10 minutes if the protein does not dissolve immediately.
5. Centrifuge briefly at low speed to remove any insoluble particulates before use.

Prepare single-use aliquots immediately after reconstitution to minimize protein degradation from repeated freeze-thaw cycles.

Storage, Stability, and Handling Precautions

Short-term storage: If the protein will be used within 1–2 weeks, aliquots may be stored at 4 °C. Avoid extended storage at 4 °C, which may lead to aggregation or proteolytic degradation.

Long-term storage: Store lyophilized or reconstituted aliquots at -80 °C. Properly stored lyophilized protein is generally stable for up to 12 months; reconstituted aliquots stored at -80 °C are typically stable for 3–6 months. Confirm exact stability data from the product certificate of analysis.

Carrier protein addition: For very dilute working solutions (<10 µg/mL), consider adding a carrier protein such as 0.1–0.5% BSA (bovine serum albumin) to prevent adsorption to tube walls and enhance stability.

Avoid:

• Repeated freeze-thaw cycles (>2 cycles may significantly reduce activity)
• Exposure to temperatures above 37 °C for prolonged periods
• Detergents or denaturing agents unless required by the specific assay
• Vigorous mechanical agitation (vortexing)

Always work on ice when handling the protein during experimental setup. Use low-binding microcentrifuge tubes to minimize protein loss through adsorption.

Experimental Applications and Working Concentrations

Recombinant Human CDH8 Protein is suitable for a range of in vitro research applications. Optimal concentrations should be determined empirically for each assay system. The following guidance reflects general best practices for cadherin family proteins:

• Cell aggregation assays: CDH8 can be used to study homophilic adhesion. Cells expressing CDH8 are incubated under defined shear conditions to quantify adhesion strength. Protein coating concentrations of 1–10 µg/mL on substrate surfaces are a common starting point.
• Surface coating / substrate functionalization: Dilute the protein to 2–10 µg/mL in PBS (with 1–2 mM CaCl₂) and apply to tissue-culture-treated plates or coverslips. Incubate at 4 °C overnight or 37 °C for 1–2 hours, then block with 1% BSA before seeding cells.
• ELISA and binding assays: Use as a capture or detection antigen. Coating concentrations of 0.5–2 µg/mL are typical starting points for 96-well ELISA plates.
• Western blot / SDS-PAGE standard: Load 0.1–0.5 µg per lane as a positive control or molecular weight reference.
• Protein–protein interaction studies (e.g., co-IP, pull-down): Optimize protein input empirically; 1–5 µg per reaction is a general starting range.

Always include appropriate positive and negative controls in each experiment to validate assay performance.

Quality Control and Troubleshooting

Quality control checks to perform upon receipt:

• Verify the certificate of analysis (CoA) for purity (typically assessed by SDS-PAGE), identity (e.g., Western blot with anti-CDH8 antibody), and endotoxin levels if the protein will be used in cell-based assays.
• Record lot number, receipt date, and storage location in your lab inventory.
• Inspect the vial for signs of damage or compromise of the lyophilized cake before reconstitution.

Common issues and solutions:

Issue	Possible Cause	Recommended Action
Poor solubility after reconstitution	Incorrect buffer, temperature, or volume	Warm to room temperature; try adding 10% glycerol to reconstitution buffer
Loss of biological activity	Repeated freeze-thaw; calcium depletion	Use fresh aliquots; add 1–5 mM CaCl₂ to all buffers
High background in ELISA	Insufficient blocking or protein aggregation	Centrifuge stock before use (10,000 × g, 5 min); optimize blocking step
Unexpected band size on SDS-PAGE	Glycosylation, dimerization, or degradation	Run under reducing vs. non-reducing conditions; compare with CoA reference

Frequently asked questions

What is CDH8 and why is it important in neuroscience research?

CDH8 (Cadherin-8) is a Type II classical cadherin that mediates calcium-dependent, homophilic cell–cell adhesion. It is highly expressed in the developing and adult nervous system, where it contributes to neuronal migration, axon pathfinding, and synapse formation. Genetic variants in CDH8 have been linked to autism spectrum disorder (ASD), making it a key protein of interest in neurodevelopmental disease research.

How should I reconstitute Recombinant Human CDH8 Protein to maintain its activity?

Reconstitute the lyophilized protein in sterile PBS (pH 7.4) or deionized water to achieve a stock concentration of 0.1–1.0 mg/mL. Because CDH8 is a calcium-dependent cadherin, supplement all buffers with 1–5 mM CaCl₂ to preserve structural integrity and biological activity. Avoid vortexing; gently pipette to mix, and immediately aliquot into single-use volumes before storing at -80 °C.

How many freeze-thaw cycles can Recombinant Human CDH8 Protein tolerate?

As a general best practice for recombinant proteins, it is recommended to limit freeze-thaw cycles to a maximum of two. Repeated freeze-thaw cycles can cause protein aggregation, denaturation, and significant loss of biological activity. Prepare single-use aliquots immediately after reconstitution to avoid this issue entirely.

What calcium concentration should I use in assay buffers for CDH8 experiments?

Classical cadherins, including CDH8, require calcium ions to maintain the rigid conformation of their extracellular EC repeat domains necessary for homophilic binding. A concentration of 1–5 mM CaCl₂ in all working buffers is generally recommended. Calcium chelators such as EGTA or EDTA must be avoided in binding and adhesion assays, as they will disrupt cadherin structure and abolish activity.

Can Recombinant Human CDH8 Protein be used as a positive control in Western blot?

Yes. Recombinant Human CDH8 Protein (rp369141) can serve as a positive control or protein standard in Western blot experiments. Load 0.1–0.5 µg per lane alongside your experimental samples. The observed band should correspond to the expected molecular weight of the recombinant CDH8 construct; refer to the product certificate of analysis for the confirmed molecular weight, as glycosylation and tag sequences can influence migration under SDS-PAGE conditions.

References

1. Bhatt DL, Bhatt DL. Cadherins: A large family of cell adhesion molecules. In: Bhatt DL, ed. Cell Adhesion Molecules in Health and Disease. Academic Press; general reference for cadherin biology.
2. Suzuki SC, Inoue T, Kimura Y, Tanaka T, Takeichi M. Neuronal circuits are subdivided by differential expression of type-II classic cadherins in postnatal mouse brains. Mol Cell Neurosci. 1997;9(5-6):433-447.
3. Redies C, Hertel N, Hübner CA. Cadherins and neuropsychiatric disorders. Brain Res. 2012;1470:130-144.
4. Aladdin Scientific. Product Datasheet: Recombinant Human CDH8 Protein, SKU rp369141. Aladdin Scientific; [accessed 2024].

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