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For Research Use Only (RUO)
$876.00
Sku: 1301301
Product Description
96-well ELISA kit for quantitative measurement of residual host cell proteins (HCPs) from E.coli protein expression strains (originating from BL21). The kit uses a double-antibody sandwich format with an affinity-purified sheep polyclonal capture antibody coated on the microtiter strips and a biotinylated sheep polyclonal detection antibody. Detection is achieved via streptavidin-HRP and TMB substrate with absorbance read at 450 nm (reference 620–650 nm). The kit is intended for research use to monitor HCPs in products expressed in E.coli BL21 (e.g., ILs, rhIFN, rhGM-CSF, rhTNF, EGF/FGF/PDGF). No special sample pre-treatment is required other than clarification and suitable dilution; method validation is recommended for each sample matrix.
Technical Specifications
| Parameter | Details |
|---|---|
| Package size | 96 tests/Kit |
| Assay format | Double-antibody sandwich ELISA (capture antibody coated microtiter strips; biotinylated detection antibody + streptavidin-HRP) |
| Linearity & Range | 1 - 243 ng/mL, R² ≥ 0.990 |
| Lower Limit of Quantification (LLOQ) | 1.5 ng/mL |
| Calibration curve model | 4-parameter logistic (4-PL). Typical 4-PL parameters: A = 2.38642; B = -1.02805; C = 85.80515; D = 0.00132; R² = 1.00000 |
| Typical calibration points (conc. ng/mL) | ST1 243; ST2 81; ST3 27; ST4 9; ST5 3; ST6 1; NCS 0 |
| Specificity | No cross-reactivity with CHO, Vero, HEK293T, and Hansenula polymorpha |
| Sample pH requirement | pH 6.5 - 8.5 |
| Sample types | In-process samples, harvested bulk, drug substance, drug product derived from E.coli BL21 expression |
| Stability note | Do not mix reagents from different lots. Reconstituted calibration standard and diluted conjugates/streptavidin-HRP are recommended for single use due to stability. |
Features
- High specificity capture/detection: Sheep polyclonal anti-E.coli HCP antibodies used for capture and biotinylated detection maximize recognition of diverse HCP species from BL21 expression strains.
- Sensitive quantitative range: Measured linear range 1–243 ng/mL with LLOQ 1.5 ng/mL using a 4-PL calibration curve.
- Complete ready-to-use kit: Includes coated microtiter strips, lyophilized calibration standard, diluent, wash buffer concentrate, biotinylated conjugate, streptavidin-HRP, TMB substrate, stop solution and sealing films.
- Standard ELISA workflow: Uses streptavidin-HRP/TMB detection compatible with standard plate readers (450 nm with 620–650 nm reference).
- Designed for BL21 expression strains: Optimized and validated for residual HCP detection in products expressed in E.coli BL21; method validation required for other strains.
Applications
- Quantification of residual host cell proteins (HCPs) in products expressed in E.coli BL21
- In-process monitoring (fermentation harvest, clarified bulk)
- Testing of drug substance and drug product for residual E.coli HCPs
- Assay support for bioprocess development and purification optimization for E.coli-expressed proteins (e.g., ILs, rhIFN, rhGM-CSF, rhTNF, EGF/FGF/PDGF)
Kit Contents
E.coli HCP-E Calibration Standard (lyophilized)Store reconstituted standard at 2-8 °C (reconstituted stability: up to 30 days).
Anti-E.coli HCP-E Microtiter Strips (pre-coated, 8-well ×12 strips)Store sealed in bag with desiccant at 2-8 °C (opened strips stable up to 60 days).
Reconstitution Solution (for calibration standard)Store at 2-8 °C.
Diluent (25 mL)Store at 2-8 °C.
Wash Buffer Concentrate (10×) (2×25 mL)Store at 2-8 °C. Dilute 10× with ultrapure water before use.
Anti-E.coli HCP-E Biotinylated Conjugate (100×)Store at 2-8 °C. Centrifuge before use; dilute freshly 1:100 with 1×Wash Buffer and use immediately.
Streptavidin-HRP (100×)Store at 2-8 °C. Centrifuge before use; dilute freshly 1:100 with 1×Wash Buffer and use immediately.
TMB Substrate (12 mL)Store at 2-8 °C protected from light; equilibrate to room temperature before use.
Stop Solution (1 M HCl, 6 mL)Store at 2-8 °C; handle with care (corrosive).
Sealing Film (3 pieces)Store at 2-8 °C.
* Total: 96 tests/Kit | Method: ELISA (double-antibody sandwich)
Attention
• For Research Use Only (RUO) — not for clinical diagnostic use.
• Use fresh ultrapure water; water temperature should not exceed 37 °C during reagent preparation.
• Avoid samples containing sodium azide (NaN3) which will inhibit HRP and underestimate HCP levels.
• Do not mix reagents from different lot numbers.
• Reconstituted calibration standard, diluted biotinylated antibody and diluted streptavidin-HRP are recommended for single use; prepare fresh for each experiment.
• Avoid repeated freeze-thaw cycles for samples; long-term storage recommended at ≤ -70 °C.
• Stop Solution is 1 M HCl — avoid contact with eyes/skin; use appropriate PPE and goggles.
• Prevent well drying and liquid evaporation; seal plate during incubations when indicated.
• Centrifuge concentrated conjugates before use to remove particulates; dilute as instructed.
• Complete plate reading within 30 minutes after adding stop solution.
Quality Management & Certifications
Quality System
Download QMSQMS (ISO, GMP)
Download CertificateQuality Advantages
View ReportQuality Control Process
Download ProcessTechnical Resources & Downloads
Frequently Asked Questions (FAQ)
Q1: How do I reconstitute the calibration standard?
Add exactly 500 µL of the provided Reconstitution Solution to the lyophilized E.coli HCP-E Calibration Standard, invert gently 3–5 times, let stand ~5 minutes until clear, then proceed to prepare serial dilutions as described (ST1–ST6).
Q2: How should opened components be stored and how long are they stable?
Store the kit and components at 2–8 °C. Opened microtiter strips (in bag with desiccant) are stable up to 60 days; reconstituted calibration standard is stable at 2–8 °C for up to 30 days. Prepare diluted conjugates and streptavidin-HRP fresh for each assay.
Q3: What sample types are compatible and what sample pH is acceptable?
Compatible sample types include in-process samples, harvested bulk, drug substance and drug product from E.coli BL21 expression. Sample pH should be between 6.5 and 8.5; otherwise assay results may be abnormal.
Q4: What causes high background and how can I troubleshoot it?
High background can be caused by reagent or equipment contamination, insufficient washing, or environment contamination. Use fresh reagents, clean equipment with 75% ethanol, increase wash volume/times, and ensure thorough removal of wash buffer before next steps.
Research Use Only
✔
Research Use Only (RUO) — Not for clinical diagnostic use – This product is intended for laboratory research purposes only and not for clinical or regulatory diagnostic use.
✔
Not intended for use in USDA or FDA regulated diagnostic testing or official compliance testing.
When can I expect my order to ship?
Most orders are filled and shipped within 2-3 business days from the time they are received.
Our standard shipping usually take 2-5 days.
We also provide express shippping for time-sensitive deliveries.
Email contact@biofargo.com if you have any requirements.
