Key Features
- Detects Total Human ApoE, All Isoforms Equally: Recognizes E2, E3, and E4 with equivalent efficiency, providing unbiased total apolipoprotein E measurement in research samples.
- Exceptional Specificity: No cross-reactivity with human ApoA1, ApoA2, ApoB, ApoB100, ApoC1, ApoC2, or ApoD. No interference from ApoE receptors. No reactivity with other soluble structural analogues.
- Clinically Relevant Unit Scale: Standard curve expressed in mg/dL (0, 0.5, 1, 2, 4, 8 mg/dL), aligning with common literature and physiological ranges.
- High Sensitivity & Appropriate Range: Minimum detectable concentration < 0.1 mg/dL; quantitative range 0.1–8 mg/dL.
- Validated Sample Types: Human serum, EDTA/citrate/heparin plasma, cell culture supernatant, and tissue homogenates.
- Tissue Protocol with Enhanced Recovery: For lipid-rich tissues such as atherosclerotic plaques, sonication or freeze-thaw steps can be incorporated to maximize apoE release without compromising assay performance.
- Hyperlipidemic Sample Guidance: Grossly lipemic specimens can cause light scattering interference. A recommended high-speed centrifugation step is provided to clear chylomicrons before assay.
- Built-in 5× Sample Dilution: The assay dilutes samples 5-fold directly in the well (10 µL sample + 40 µL diluent). Multiply the interpolated value by 5 to obtain the actual concentration.
- Recombinant Protein Standards: Produced in a eukaryotic expression system, ensuring native-like conformation and immunoreactivity.
- One-Step Workflow: Simultaneous incubation of sample/standard and HRP-conjugated antibody; total assay time approximately 2 hours.
- Reliable Precision: Intra- and inter-assay CV < 15%; standard curve linearity R ≥ 0.9900.
- Flexible Formats: 48-well and 96-well plates with removable strips; up to 88 samples per plate (single wells).
- Storage & Stability: 6-month shelf life at 2–8°C, protected from light and moisture; cold-chain shipping.
Product Description
Apolipoprotein E (ApoE) is a 34-kDa glycoprotein that mediates lipoprotein clearance, cholesterol homeostasis, and lipid transport. In the central nervous system, apoE is produced by astrocytes and plays a critical role in neuronal repair, synaptic plasticity, and amyloid-β metabolism. Human apoE exists in three major isoforms (E2, E3, E4), each associated with distinct risks for cardiovascular disease and Alzheimer’s disease. Accurate quantification of total apoE, independent of isoform bias, is essential for translational research in dyslipidemia, atherosclerosis, and neurodegeneration.
The Yanda-HUMAN-Apo-E ELISA Kit uses a one-step double-antibody sandwich ELISA. A pre-coated capture antibody binds a common epitope on human apoE, and an HRP-conjugated detection antibody is added simultaneously. After washing, TMB substrate generates a signal proportional to the apoE concentration. Absorbance is read at 450 nm.
Sample Collection & Preparation
Liquid Samples
| Sample Type | Procedure |
|---|---|
| Serum | Collect in pyrogen/endotoxin-free tubes. Let clot, then centrifuge at 3000 rpm for 10 min. Separate serum immediately. |
| Plasma | Use EDTA, citrate, or heparin. Centrifuge at 3000 rpm for 30 min; collect supernatant. |
| Cell Culture Supernatant | Centrifuge at 3000 rpm for 10 min to remove cells and debris. |
Hyperlipidemic Samples – Critical Pre-Treatment
Grossly lipemic (milky) samples contain chylomicrons that scatter light and directly interfere with absorbance at 450 nm, causing falsely elevated readings or high variability. Do not use turbid samples without clarification.
- Centrifuge the lipemic sample at 10,000 × g for 10 minutes (or 2000–3000 rpm for 20 minutes at 2–8°C).
- Carefully collect the clear middle layer for testing. Discard the top lipid layer and bottom pellet.
Tissue Homogenates
For routine tissues, use ice-cold PBS (0.01 M, pH 7.4) or tissue homogenization buffer containing fresh protease inhibitors (e.g., 1 mM PMSF). Homogenize on ice and centrifuge at 3000 rpm for 10 min at 4°C; collect the supernatant.
Enhanced Recovery for Lipid-Rich or Fibrotic Tissues (e.g., Atherosclerotic Plaques)
To improve apoE extraction from tissues rich in extracellular matrix and lipoprotein particles:
- Mince tissue and add ice-cold PBS with protease inhibitors.
- Homogenize thoroughly on ice.
- Optional: Perform sonication (on ice) or 2–3 freeze-thaw cycles to disrupt cells and release lipoprotein-bound apoE.
- Centrifuge at 5000 × g for 5–10 minutes at 4°C. Collect the clear supernatant.
Triton X-100 at concentrations used in routine lysis buffers does not interfere with the assay.
Storage
If not assayed immediately, aliquot and store at -20°C. Avoid repeated freeze-thaw cycles. Thaw completely at room temperature and mix gently before use.
Critical Dilution Factor
The assay applies a 5-fold dilution in the well (10 µL sample + 40 µL Sample Diluent). The concentration read from the standard curve reflects the diluted sample. Multiply the result by 5 to obtain the actual apoE concentration in the original specimen.
The S0 standard (0 mg/dL) serves as the blank/negative control.
Baseline Reference: Normal human serum/plasma apoE levels typically range from 2 to 6 mg/dL depending on age, sex, and genetic background (literature values). We recommend establishing your own laboratory reference range through pilot experiments.
Technical Specifications
| Parameter | Specification |
|---|---|
| Standard Concentrations (S0–S5) | 0, 0.5, 1, 2, 4, 8 mg/dL |
| Quantitative Range | 0.1 – 8 mg/dL |
| Analytical Sensitivity | < 0.1 mg/dL |
| Accuracy (Linearity) | Standard curve R ≥ 0.9900 |
| Precision | Intra-assay CV < 15%; Inter-assay CV < 15% |
| Specificity | Equally recognizes E2, E3, E4 isoforms. No cross-reactivity with human ApoA1, ApoA2, ApoB, ApoB100, ApoC1, ApoC2, ApoD. No interference from ApoE receptors. No cross-reactivity with other soluble structural analogues. |
| Species Restriction | Validated exclusively for human samples; not recommended for cross-species use. |
| Sample Dilution Factor | 5× (automatically performed in the well) |
| Shelf Life | 6 months |
| Storage & Transport | 2–8°C, protected from light and moisture; cold-chain shipping |
Representative Standard Curve
For spike-recovery, dilution linearity, and other validation data, please refer to the product instruction manual or contact technical support.
Kit Components
96-Well Format
| Component | Quantity | Notes |
|---|---|---|
| Microelisa Stripplate | 12 strips × 8 wells | Pre-coated with anti-human apoE antibody |
| Standard (0.3 mL/vial) | 6 vials | Ready-to-use liquid, 0–8 mg/dL |
| Sample Diluent | 6 mL | – |
| HRP-Conjugated Detection Antibody | 10 mL | Ready-to-use |
| 20× Wash Buffer | 25 mL | Dilute to 1× before use |
| Substrate A | 6 mL | – |
| Substrate B | 6 mL | – |
| Stop Solution | 6 mL | – |
| Plate Sealers | 2 sheets | – |
| Instruction Manual | 1 copy | – |
| Self-sealing Bag | 1 piece | For storing unused strips |
48-Well Format
| Component | Quantity | Notes |
|---|---|---|
| Microelisa Stripplate | 12 strips × 4 wells | Pre-coated, removable |
| Standard (0.3 mL/vial) | 6 vials | Ready-to-use liquid |
| Sample Diluent | 3 mL | – |
| HRP-Conjugated Detection Antibody | 5 mL | Ready-to-use |
| 20× Wash Buffer | 15 mL | Dilute to 1× |
| Substrate A | 3 mL | – |
| Substrate B | 3 mL | – |
| Stop Solution | 3 mL | – |
| Plate Sealers | 2 sheets | – |
| Instruction Manual | 1 copy | – |
| Self-sealing Bag | 1 piece | – |
Note: The 20× Wash Buffer may crystallize during cold storage; warm in a water bath until crystals dissolve completely before dilution.
Assay Procedure Summary
- Equilibrate: Let the foil pouch reach room temperature for 20 min. Remove required strips; reseal unused strips and store at 4°C.
- Add Standards & Samples:
- Standard wells: 50 µL of each standard.
- Sample wells: 10 µL sample + 40 µL Sample Diluent.
- Blank well(s): Leave empty.
- Add Detection Antibody: Dispense 100 µL of HRP-conjugated detection antibody into all wells except blank. Cover and incubate at 37°C for 60 minutes.
- Wash: Aspirate, blot dry. Fill wells with 1× Wash Buffer, let stand for 1 min, discard. Repeat for a total of 5 washes (automated: 350 µL/well, 1-min soak).
- Substrate: Add 50 µL each of Substrate A and Substrate B. Incubate in the dark at 37°C for 15 minutes.
- Stop & Read: Add 50 µL Stop Solution. Read absorbance at 450 nm within 15 minutes.
Total hands-on time: approximately 2 hours.
Materials Required but Not Supplied:
- Microplate reader (450 nm)
- Adjustable pipettes and tips (0.5–1000 µL)
- 37°C incubator or water bath
- Distilled/deionized water
- Absorbent paper, wash bottle or automated plate washer
- Protease inhibitors (for tissue homogenization)
Throughput
| Format | Max. Number of Samples (Single Wells) |
|---|---|
| 48-well | 39–40 samples |
| 96-well | 85–88 samples |
Includes 6 standard wells and 1–2 blank wells. For duplicate measurements, divide the sample number accordingly.
Related ELISA Kits
To build a comprehensive lipid metabolism panel, researchers often pair this assay with:
- MHPG Biotin ELISA Kit
- Human Estrone-3-sulfate (E3S) ELISA Kit – Quantitative Sulfated Estrogen Immunoassay for Pharmacological & Oncology Research
- Human Collagen Type (Col) ELISA Kit – Total Collagen Quantitative Assay for Research
- Horse IL-1β ELISA Kit – Quantify Equine Interleukin-1β with Confidence
Frequently Asked Questions
Q: Why multiply the result by 5?
A: The assay automatically dilutes the sample 5-fold in the well (10 µL sample + 40 µL diluent). The standard curve is constructed identically; the interpolated value is the diluted concentration. Multiply by 5 for the actual sample value.
Q: Does this kit distinguish between apoE2, E3, and E4?
A: No. It detects total apoE and recognizes all three major isoforms with equivalent efficiency. It is not designed for isoform-specific quantitation.
Q: What cross-reactivity has been tested?
A: The kit shows no cross-reactivity with human ApoA1, ApoA2, ApoB, ApoB100, ApoC1, ApoC2, or ApoD. No interference from ApoE receptors has been observed.
Q: Can I use lipemic samples?
A: Grossly lipemic samples must be clarified first. Centrifuge at 10,000 × g for 10 minutes (or 2000–3000 rpm for 20 min at 2–8°C) and use the clear middle layer. Turbid samples will cause unreliable OD readings at 450 nm.
Q: How should I prepare atherosclerotic plaque tissue?
A: Homogenize in ice-cold PBS with protease inhibitors, then perform sonication (on ice) or freeze-thaw cycles to enhance apoE release. Centrifuge at 5000 × g for 5–10 min at 4°C and use the clear supernatant.
Q: Can this kit be used for mouse or other animal samples?
A: No. It has been validated exclusively for human samples. Cross-species use is not recommended.
Q: What if my result exceeds 8 mg/dL after multiplying by 5?
A: Pre-dilute the sample further with the provided Sample Diluent (e.g., 1:2 or 1:5), re-assay, and multiply by all dilution factors.
Other Frequently Asked Questions in ELISA Test
Ordering & Contact Information
| Item | Details |
|---|---|
| Catalog Number | Yanda-HUMAN-Apo-E |
| Formats | 48-well / 96-well |
| Package Dimensions | 16 cm × 12.5 cm × 9.5 cm (neutral white box) |
| Shipping | Cold-chain transport (2–8°C), protected from light and moisture |
| Storage | 2–8°C; do not freeze |
| Shelf Life | 6 months |
| Intended Use | For research use only, not for diagnostic procedures |
Contact us
- WhatsApp: +86 198 3186 0669
- Email: songhawyble@gmail.com
For pricing, bulk orders, or customization, please contact us directly.
Technical Documents & Support
- MSDS – Supplied with the kit or upon request.
- Technical Support – For validation data, protocol advice, or troubleshooting, reach out via WhatsApp or email.
Disclaimer
This product is for laboratory research use only and is not approved for clinical diagnosis, treatment, or prognosis. The manufacturer assumes no responsibility for consequences arising from improper use, protocol deviations, or unauthorized applications. Users are responsible for validating the assay in their own sample matrix and experimental conditions.
