sentence2_structure: A viral vector<>is<>the name for a tool$$$a tool<>commonly used<>by molecular biologists<>to place genetic material into cells$$$A viral vector<>is the name for<>a tool
sentence1: The laboratory uses a combination of genetic manipulations, molecular  biology, and animals studies to identify the function of these two viral gene products and to identify other viral genes which regulate cell tropism.
sentence2: A viral vector is the name for a tool commonly used by molecular biologists to place genetic material into cells.
question: What is the name for a tool commonly used by molecular biologists to place genetic material into cells?