Lamivudin var ikke mutagent i bakterieforsøg, men viste som mange andre nukleosidanaloger aktivitet i en in vitro- cytogenprøve og i muselymfomcelletesten.
Lamivudine was not mutagenic in bacterial tests but, like many nucleoside analogues, showed activity in an in vitro cytogenetic assay and the mouse lymphoma assay.