Antibody System Rituximab ELISA Kit

Principle of the Assay

This assay utilizes a high-performance, solid-phase quantitative competitive enzyme immunoassay technique to measure target drug levels:

• Target Capture: Recombinant Human CD20 protein is uniformly pre-coated onto the solid-phase surface of a 96-well microplate.

• Competitive Binding: Calibrated standards or unknown biological samples are premixed with a biotin-labeled antibody component and pipetted into the microplate wells. Endogenous Rituximab present within the sample competes directly with the biotin-labeled tracer molecule for a limited number of immobilized CD20 binding domains.

• Enzyme Conjugation: Unbound components are removed via a rigorous wash cycle. Streptavidin conjugated to Horseradish Peroxidase (Streptavidin-HRP) is introduced into the wells, anchoring specifically to the remaining biotin-labeled antibody fractions.

• Signal Amplification and Readout: Following a final wash to remove excess enzyme reagent, a colorimetric substrate solution is added to initiate enzymatic signal development. Because this is a competitive assay format, the resulting color intensity is inversely proportional to the concentration of active Rituximab present in the initial sample matrix. The reaction is terminated with a stop solution, and absorbance is quantified spectrophotometrically.

Key Features and Performance Metrics

• Refined Sensitivity Profile: Exhibits a lower limit of detection (LLD) down to 23.65 ng/mL, allowing investigators to monitor low-level therapeutic clearance and trough concentrations.

• Dynamic Range Framework: Delivers a reliable linear range tracking from 31.25 ng/mL to 2,000 ng/mL to seamlessly accommodate diverse sample concentrations.

• Intra-Assay Precision Profile: Demonstrates consistent target reproducibility with a Coefficient of Variation (CV) of less than 20 percent, validated through sixteen separate replicate evaluations across three samples of known concentration on a single test plate.

• Inter-Assay Precision Profile: Confirms high batch-to-batch and day-to-day experimental uniformity with a CV of less than 20 percent, verified across twenty-four distinct assay runs using three independent reference concentration samples.

Technical Specifications

• Catalog No.: KDC90709

• Assay Configuration: Quantitative Competitive Enzyme Immunoassay

• Targeted Biomarker: Rituximab (Anti-CD20 Therapeutic Antibody)

• Validated Matrices: Serum and Plasma

• Assay Range: 31.25 to 2,000 ng/mL

• Analytical Sensitivity: 23.65 ng/mL

• Solid-Phase Target: Recombinant Human CD20

• Detection Enzyme Layer: Streptavidin-HRP Conjugate

Applications and Workflow Summary

This competitive ELISA platform is optimized for high-throughput pharmacological profiling and downstream clearance evaluations. Investigators should observe the following guidelines:

• Dilution and Layout: Unknown serum or plasma matrices should be screened alongside the provided reference standards. Samples exhibiting concentrations exceeding the maximum range of 2,000 ng/mL must be diluted empirically in standard assay matrix buffer prior to running the assay.

• Analysis Requirements: To achieve absolute quantification accuracy, investigators must generate a standard curve simultaneously during every plate run, plotting standard absorbance profiles against log-transformed concentration values.

Handling, Stability and Storage

• Kit Shipping: Distributed under secure, temperature-controlled conditions on blue ice or chilled gel packs to preserve protein and enzyme binding configurations.

• Operational Shelf Life: When stored continuously at the designated, recommended kit temperature, the internal signal intensity and enzymatic reactivity profile degrade by less than 20 percent over a six-month framework.

• Storage Guidance: Keep the complete kit stored strictly at the manufacturer-specified refrigeration temperature upon receipt. Ensure that unused microplate wells remain sealed within their original desiccant pouch to guard against moisture compromise.