Bio‑Techne Corporation, a global provider of life science tools, reagents, and diagnostic products, and Refeyn, a pioneer in mass photometric technology, today announced a first-of-its-kind integrated workflow for the characterization of charge and size variants of bispecific antibodies and biosimilars.
By combining the R&D Systems MauriceFlex™ Imaging Capillary Isoelectric Focusing (icIEF) fractionation system with Refeyn’s TwoMP mass photometry platform, researchers can directly correlate charge heterogeneity with molecular weight and aggregation at single-molecule resolution in a streamlined 4-hour workflow.
Bispecific antibodies are one of the fastest growing classes of biopharmaceuticals, but their structural complexity makes thorough characterization difficult. Incomplete characterization can delay development, increase manufacturing risk, and lead to costly late-stage failures.
The MauriceFlex™ system provides high-resolution separation and fractionation of charge variants. This feature is increasingly expected in regulatory filings. However, traditional methods require large sample sizes, making it historically difficult to analyze the size and aggregation of individual charge moieties.
An integrated workflow directly addresses this challenge by combining icIEF fractionation and mass photometry. Charge variants are first separated using MauriceFlex™ and then analyzed on Refeyn’s TwoMP platform. This platform requires only nanogram-level samples and reveals size distribution and aggregation with single-molecule resolution.
Combining these technologies enables direct characterization of aggregation and size within the charge variations resolved with icIEF. This is insight not available with standalone methods, reducing reliance on multiple tests and enabling faster, more efficient process development.
Bispecific antibodies are the fastest growing segment of next-generation antibodies, but they are extremely difficult to characterize. This approach directly addresses one of the biggest challenges by combining icIEF fractionation with mass photometry. Researchers can now examine charge and size variations together in a single workflow. ”
Jerry McKay, Refeyn CEO
“Our customers are under intense pressure to develop and manufacture increasingly complex biologics faster and more efficiently. Enabling deeper characterization with fewer samples helps reduce risk, control costs and make better decisions early in development.” Will Geist, president of Bio‑Techne’s protein science division, said:
In a joint webinar, the scientists demonstrated a workflow using mosnetuzumab-axgb and biosimilars to track size-related changes in molecules across charge variant fractions under multiple conditions. An application note with complete findings is available here.
This workflow will also be presented at the American Society for Mass Spectrometry (ASMS) conference in San Diego from May 31 to June 4, 2026. Click here for booth and poster details.

