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Updated: Feb 5, 2026

Development and Validation of an Ultrasensitive Single Molecule Array Digital Enzyme-linked Immunosorbent Assay for Human Interferon-α
Published on: June 14, 2018
Optimization and qualification of the single molecule array digital immunoassay for IL-12p70 in plasma of cancer
Vinita Gupta1, Navdeep Kalia1, Mahesh Yadav2
1Bioanalytical Sciences, Genentech Inc, 660 E. Grand Avenue, South South San Francisco, CA 94080, USA.
Aim:
Cytokine/chemokine levels can reflect the pharmacodynamics of checkpoint inhibitors. The single molecule array (Simoa) HD-1 is a sensitive next-generation immunoassay platform for quantification of low abundance proteins, with potential for cancer immunotherapy mechanism of action studies.
Results:
The Simoa IL-12p70 reagents, standard curve and test conditions were optimized for improved precision and linearity of dilution in plasma of cancer patients. The assay achieved a lower limit of quantification of 0.08 pg/ml, with 27/29 samples recording above lower limit of quantification, precision ≤20% CV and accuracy within 80-120%.
Conclusion:
Simoa enabled quantification of IL-12p70 at sub-pg/ml levels in cancer patients and was superior to Simple Plex™ and Aushon® in overall performance. This study qualifies the user-modified IL-12p70 immunoassay to measure pharmacodynamic changes in plasma during cancer immunotherapy.
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