Exploring the Breadth of “Custom Assay” Services: Immunoassays (ELISA, CLIA), Molecular Assays (qPCR), Cell-Based Assays, Multiplex Platforms

Within ExCell Bio, assay development is viewed as an applied scientific discipline built around validation, reproducibility, and experimental relevance. A custom assay is rarely a single technique; instead, it represents a tailored combination of platforms designed to address specific biological questions. Supported by structured analytical method development, our custom assay services span immunoassays, molecular assays, cell-based systems, and multiplex formats, allowing B2B partners to align experimental design with real-world research and production needs.

Immunoassays Built for Defined Performance Requirements

Immunoassays form a core component of many custom assay programs at ExCell Bio, including ELISA and chemiluminescent immunoassays. These formats rely on controlled antigen–antibody interactions, signal detection strategies, and optimized assay conditions. Throughout development, analytical method development provides the framework to assess specificity, sensitivity, and background signal under standardized conditions.

By applying analytical method development early, we ensure that immunoassay parameters are evaluated using repeatable procedures rather than trial-and-error adjustments. This approach allows each custom assay to be aligned with its intended application, whether for biomarker quantification or screening workflows. Consistent evaluation methods also support smoother transitions between development stages.

Molecular and Cell-Based Assays as Functional Readouts

Beyond immunoassays, custom assay services at ExCell Bio include molecular assays such as quantitative PCR and a range of cell-based formats. Molecular assays are developed with attention to primer design, amplification efficiency, and signal linearity, all assessed through established analytical method development protocols.

Cell-based assays introduce additional complexity, as biological responses depend on cellular context and assay conditions. For these systems, analytical method development helps define readout stability, assay timing, and response consistency. By combining molecular and cellular platforms within a custom assay, we enable functional evaluation that extends beyond static measurements and reflects biologically relevant activity.

Multiplex Platforms and Integrated Method Development

Multiplex platforms allow simultaneous measurement of multiple targets within a single custom assay, increasing data density while conserving samples. At ExCell Bio, multiplex development is managed through careful control of cross-reactivity, signal overlap, and assay compatibility. Analytical method development supports this process by providing structured testing strategies that compare single-plex and multiplex performance.

Integration across platforms requires consistent evaluation criteria. By applying the same analytical method development principles to immunoassays, molecular assays, and multiplex systems, we maintain comparability across different custom assay formats. This consistency helps partners interpret results across platforms without introducing methodological uncertainty.

At ExCell Bio, a custom assay is defined by scientific alignment rather than technique alone. Whether addressing immunoassays, molecular assays, cell-based systems, or multiplex platforms, analytical method development serves as the unifying structure that supports reliability and technical clarity. By embedding method validation into every custom assay we develop, we provide B2B partners with experimentally grounded solutions designed for reproducible and meaningful outcomes.