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Accurate determination of free antigens in 100% serum using Gyrolab
Date: 2025-11-05Read: 1
Gregor Jordan et al. from Roche developed an immunoassay method for detecting free antigens in whole serum based on the Gyrolab platform. The method aims to address the challenges in free substance analysis, including:
The dilution of the sample leads to the dissociation of the antigen antibody complex,Overestimating the concentration of free antigen
The half-life of antibody antigen complexes is short (<100 seconds), and traditional LBA methods cannot accurately capture them
It is difficult to distinguish between free and bound antigens in the presence of therapeutic antibodies
This method adopts the principle of bridging immunoassay, and the specific steps are as follows:
1
Coat the labeled capture antibody onto a streptavidin affinity column
2
joinUndiluted serum sampleTo bind free antigens with captured antibodies
3
joinLabeled detection antibodiesBinding to another epitope of the antigen
4
Detection signal, quantitative free antigen
Key requirements of the method
Capture antibodies and detect antigen epitopes recognized by antibodiesnon-overlapping
Capture antibodies and therapeutic antibodiesCompete to bind to the same epitope of the antigen
Very short incubation time (preferably<2 seconds)
No need for sample dilution to avoid complex dissociation
Research Objective
Evaluate the "clearance efficiency" of antibody drugs on CCL2, that is, whether the antibody effectively binds and clears free CCL2.
研究method
Platform and Methods
Experimental Design
Calibration curve and quality control
Calibration range: 2430 pg/mL → 10 pg/mL
QC sample:
High QC：1820 pg/mL
Mid QC：230 pg/mL
Low QC：30 pg/mL
Acceptance criteria
± 20% deviation, CV < 15%
Drug intervention group
CNTO0888: Monospecific anti-CCL2 antibody (control)
CKLO2-SG1095: Bispecific anti-CCL2 antibody (experimental group)
Concentration setting：
Low dose: 7.5 ng/mL or 15 ng/mL
High dose: 10 μ g/mL
Results and Discussion
CNTO0888 almost completely eliminates free CCL2 at high concentrations
The clearance efficiency of CKLO2-SG1095 is slightly lower, but still significantly better thanblank group
At low doses, dual antibodies still have moderate clearance ability, indicating their dose-dependent nature
Research Objective
Quickly and accurately measure the concentration of free complement C5 in undiluted serum samples for evaluating the in vivo efficacy of anti-C5 antibody drugs such as eculizumab and crovalimab.
研究method
Platform and Methods
experimentresult
Linear range of standard curve: 0.55-3000ng/ml
LOQ：0.5 ng/mL， Capable of detecting<0.1% free C5(Total C5 ≈ 400 nM)
Summary
Advantages of Method and Technology
The Gyrolab platform has a no incubation flow-through mode,Greatly reduce non-specific binding in the matrix and effectively reduce matrix interferenceIn free substance analysis, it can supportWhole serum testingAnd alsoReduce the dissociation of antibody antigen complexes caused by incubationMake the analysis of free substances more accurate and efficient.
References:
[1] Method for determining the free antigen of an antibody in a sample, Gregor Jordan, Martin Schaefer, Maria Viert; Pub No. US2023/0393125 A1。