Abstract
Zebrafish xenograft models are increasingly recognized for predicting patient responses to cancer therapeutics, suggesting their potential as clinical diagnostic tools. However, precise microinjection of cancer cells into numerous small and fragile zebrafish larvae is laborious, requires extensive training for new operators, and often yields variable results, limiting their clinical and drug discovery applications. To address these challenges, we have designed, built, and validated an automated microinjection robot. The robot performs injections into the vasculature, perivitelline space, and hindbrain ventricle in both fully automated and semi-automated modes. Combined results demonstrate an average injection success rate of approximately 60% and larvae survival exceeding 70%, comparable to manual methods, with the fully automated mode being twice as fast. This automation reduces the need for extensive personnel training while enhancing reproducibility, efficiency, and accuracy, paving the way for more extensive use of zebrafish xenograft models in drug discovery and patient diagnostics.