Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
Immunofluorescence microscopy image of a mouse kidney section; lateral cell membranes are stained with an antibody against cadherin (green), nuclei with DAPI (red). Micrograph courtesy of Dario Neri; artistic adaptation by Erin Boyle. Article p291
Validation and comparison of previously unknown microRNA genes in related herpesviruses yielded several surprises, most notably in regard to viral evolution and microRNA biogenesis. An explosion of literature has recently appeared describing the identification and mechanism of action of microRNAs (miRNAs)—small RNA regulators of gene expression in plant and animal cells.
Real-time PCR is the favored method for measuring gene expression. Researchers benefit from a vast and growing choice of reagents and instruments for their experiments. Laura Bonetta reports.
The uptake of DNA is markedly enhanced when the nucleic acid is presented as a coprecipitate of calcium phosphate and DNA1. The insoluble precipitate attaches to the cell surface and is brought into the cells by endocytosis. Since the publication of the original method1, increases in efficiency have been achieved by including additional steps such as glycerol shock2 and/or chloroquine treatment3. This protocol is a modified version of a published method4, in which calcium phosphate–based transfection methods for Chinese hamster ovary cells and the 293 line of human embryonic kidney cells were rigorously optimized. The protocol is easily adapted for use with other types of cells, both adherent and nonadherent.