Octet® ProA and ProA-MAX Biosensors for Rapid, Accurate, High-Throughput IgG Quantitation
Measure antibody concentration directly from crude lysates, cell culture supernatants, and complex matrices with fast results, wide dynamic range, high precision and strong correlation to HPLC.
- Direct measurement of immunoglobulins (IgG) titer
- Crude Sample analysis without purification or serial dilution
- Fast turnaround of results
- Wide dynamic range
- High Precision and Correlation to HPLC
Octet® ProA and ProA-MAX biosensors enable rapid antibody quantitation from crude lysates, cell culture supernatants and complex matrices. The direct quantitation assay format provides IgG titer in less than 2 minutes and can be automated for high-throughput screening efforts.
Results correlate to HPLC data, supporting fast and reliable titer measurement in process development and analytical workflows. Using an established pH-based regeneration protocol, the biosensors can be regenerated multiple times to provide a cost-effective and time-saving assay format.
Comparison of IgG Quantitation Methods
ProA and ProA-MAX Biosensors, HPLC, and UV/Vis A280
The table compares key analytical approaches for IgG/protein quantitation, highlighting their performance, throughput, sample requirements, costs, and typical application areas in research, bioprocess monitoring, and quality control (QC).
| Octet® ProA Biosensor | Octet® ProA-MAX Biosensor | HPLC (Protein A or similar) | UV/Vis (A280) | |
|---|---|---|---|---|
| What is measured | IgG 1, 2 and 4 directly via protein A binding | IgG 1 and polyclonal IgG directly via modified protein A binding | IgG (Protein A column) or specific protein via calibrated peak area | Total protein; IgG if pure and extinction known |
| Ease of use | Easy – assay setup + calibration, instrument know‑how; plate-based workflows are user-friendly once established | Easy – assay setup + calibration, instrument know‑how; plate-based workflows are user-friendly once established | Low–Medium – method development, column care, integration & calibration; requires chromatography expertise | High – very simple; pipette sample, measure A280 |
| Typical assay time (per plate / run) | 2-30 min for a 96-well plate (instrument depending) | 2-30 min for a 96-well plate (instrument depending) | 25 min/sample (often 1–10 samples depending on injection sequence); gradient methods longer | Seconds per sample (single cuvette) or a few minutes for a microplate |
| Hands‑on time | Low–Medium – load plate, prepare standards/samples; minimal per run | Low–Medium – load plate, prepare standards/samples; minimal per run | Medium–High – sample prep, vial loading, method setup, post‑run data handling | Very low – pipette and read |
| Throughput | High | High | Low | High |
| Price per sample (consumables only) | 1 €/$ per sample (with biosensor regeneration) | 1 €/$ per sample (with biosensor regeneration) | 2–10 €/$ per sample | 0.05–0.10 €/$ per sample |
| Limit of Detection | <1 µg/mL | 10 µg/mL | ≤ 1 µg/mL | 50–100 µg/mL |
| CV% (intra-assay precision) | Typically <10% CV for IgG quant under good conditions | Typically <10% CV for IgG quant under good conditions | Typically ~1–5% CV for IgG peak area with good method and calibration | Often ~1–5% CV if pipetting is precise and samples clean; higher if matrix interferes |
| Accuracy for IgG in complex matrices | Very good – Protein A highly specific to IgG even in crude/conditioned media; requires proper calibration | Very good – customer-engineered Protein A highly specific to IgG even in crude/conditioned media; requires proper calibration | Very good – chromatographic separation + calibration; standard method in QC | Poor–Moderate – strong matrix dependence; accurate only for relatively pure IgG with known extinction coefficient |
| Dynamic range | 2–5 logs (0.025–2000 µg/mL) | 2–3 logs (100–12,000 µg/mL) | ~2–3 logs with proper calibration and detector linearity | 2–3 logs typically; often ~0.05–20 mg/mL for IgG, instrument-dependent |
| Sample volume requirement | Low – typically ~50–200 µL per well/sample | Low – typically ~50–200 µL per well/sample | Low – ~10–100 µL per injection plus any dilutions | Very low – a few µL (microvolume) to 50–100 µL in cuvettes; ~200 µL per well in plates |
| Method development effort | Low – need to optimize buffer, regeneration, loading time, standard curve, etc. | Low – need to optimize buffer, regeneration, loading time, standard curve, etc. | High – method development, column selection, gradient, robustness studies | Very low – essentially just set pathlength and buffer blank |
| Suitability for high-throughput screening | Excellent – designed for HT IgG titer and binding screens in 96–384-well formats | Excellent – designed for HT IgG titer and binding screens in 96–384-well formats | Limited – HPLC can be automated but is slower and less scalable for very large sample sets | Very good for quick approximate quantitation; excellent throughput with plates |
| Regulatory/QC suitability | Increasingly used in development/QC | Increasingly used in development/QC | Gold standard in many QC environments for quantitative assays | More for in‑process checks and formulation; not a primary QC release method for complex samples |
| Key advantages | Fast, specific IgG quant, high throughput, compatible with crude matrices | Fast, high throughput, specific IgG quant, compatible with crude matrices | High accuracy, specificity, robust, well accepted in regulated environments | Cheapest, simplest, very fast; minimal consumables |
| Key limitations | Consumable cost (biosensors), instrument cost; method still needs calibration & maintenance | Consumable cost (biosensors), instrument cost; method still needs calibration & maintenance | Lower throughput, higher method complexity and cost; more maintenance | Low selectivity and matrix sensitivity; assumes purity and correct extinction coefficient |
When to use which
Protein A biosensors
Best for: high-throughput IgG titer in clone screening, cell line development, process development and DoE runs.
You value: speed + IgG specificity + crude sample analysis (without purification or serial dilution) + high accuracy in both crude and purified samples.
HPLC
Best for: QC/lot release, stability studies where regulatory robustness and specificity are critical.
You value: highest confidence in quantitation, chromatography-based separation, traceable calibration.
UV/Vis
Best for: fast checks of concentration for purified IgG or proteins; formulation and routine lab work where high accuracy in complex matrices is not essential.
You value: minimal cost, simplicity, and very fast turnaround.
Shop ProA Biosensors
Featured Resources
Additional Resources
Octet® ProA-MAX Biosensors for High Titer IgG Quantitation - Comparable Performance with Protein A HPLC
PDF | 302.1 KB
High Throughput Bio-Layer Interferometry in Therapeutic Antibody Discovery and Development
PDF | 456.1 KB
CaptureSelect Affinity Ligands For Antibody Detection And Characterization
PDF | 1.3 MB
