Scientists use techniques such as microscopy, cell culture, and genetic engineering to study biology at the cellular level. Microscopy allows scientists to visualize cells and their organelles in detail. Cell culture techniques enable scientists to grow and study cells outside of the organism. Genetic engineering techniques such as CRISPR-Cas9 can be used to manipulate and study genes in living cells. With these techniques, scientists can explore the functions and processes of cells and their organelles.