Ganciclovir-d5 is the stable isotope-labeled counterpart of Ganciclovir. Ganciclovir is a nucleoside analog mainly used to inhibit the replication of human cytomegalovirus (CMV). Ganciclovir inhibits viral DNA polymerase and interferes with viral DNA synthesis, thereby preventing viral replication. In vitro studies show that Ganciclovir has an IC?? against CMV of approximately 0.01 μM, indicating high antiviral activity. Due to its stable isotope labeling properties, Ganciclovir-d5 is commonly used as an internal standard in pharmacokinetic studies and mass spectrometry analysis to improve detection accuracy and sensitivity. The dose or concentration used in experiments typically depends on the experimental design and research objectives.