SACF and GILA for in vitro transformation assessment of CRISPR/Cas9-edited cell therapy candidates: a multi-site study

A new publication from HESI Global’s Cell and Gene Therapy – TRAcking, Circulation, & Safety (CGT-TRACS) Committee reports findings from an international study evaluating two in vitro assays for assessing the transformation potential of CRISPR/Cas9-edited cells. The study provides evidence on the performance of these assays as animal-free tools that may contribute to tumorigenicity risk assessment during cell therapy development.

• Researchers from AstraZeneca, Bristol Myers Squibb, Novartis, and Sanofi evaluated the Soft Agar Colony Formation (SACF) and Growth in Low Attachment (GILA) assays across four independent laboratories.
• Both assays demonstrated reproducibility across sites and achieved a limit of detection of 0.8% edited cells at most participating laboratories.
• The study identified factors influencing assay performance and found that SACF offered a broader dynamic range and slightly stronger interlaboratory correlation than GILA.

Read the full publication here: Dorsheimer et al., 2026. SACF and GILA for in vitro transformation assessment of CRISPR/Cas9-edited cell therapy candidates: a multi-site study. Gene Therapy. https://www.nature.com/articles/s41434-026-00635-z

Learn more about the CGT-TRACS Committee