Detection System Lacks Sensitivity for Target Concentration (ELISA (Signal Problems))

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Accepted Answer

Low or no signal despite proper assay setup. High concentration samples may show weak signal while low concentration samples are undetectable. Common causes: 1) Colorimetric detection lacks sensitivity for low-abundance targets 2) Direct detection format provides insufficient signal amplification 3) Detection substrate produces weak signal with the conjugated enzyme 4) Target concentration is below the detection limit of the current system Solutions: 1) Switch from colorimetric to fluorescence detection for 10-100 fold sensitivity increase 2) Use indirect detection format instead of direct to add amplification step 3) Implement signal amplification using biotinylated antibodies with streptavidin-HRP 4) Use enhanced chemiluminescent substrates for HRP (e.g., SuperSignal, Femto substrates)