<h4>Purpose</h4>To develop a microbubble-based contrast agent using light-activated site-specific conjugation (LASIC) for targeted molecular ultrasound imaging of glypican-3 (GPC3) positive hepatocellular carcinoma (HCC).<h4>Materials and methods</h4>Azide-functionalized microbubbles were conjugated with commercially available anti-GPC3 antibodies using a LASIC DBCO adapter, which enables precise site-specific labeling at the antibody's heavy chain without compromising antigen-binding affinity. This evidence concerns the gene GPC3 and hepatocellular carcinoma.