The various levels of electrical signal from the sequence of a DNA strand pulled through a nanopore reader (top) corresponds to specific DNA nucleotides, thymine, adenine, cytosine and guanine (bottom). Researchers have devised a nanoscale sensor to electronically read the sequence of a single DNA molecule, a technique that is fast and inexpensive and could make DNA sequencing widely available.

New biological research reveals how an invading virus hijacks a cell's workings by imitating a signaling marker to defeat the body's defenses. By manipulating cell signals, the virus destroys a defensive protein designed to inhibit it. This finding, from studies in human cell cultures, may represent a broader targeting strategy used by other viruses, and may lay the scientific groundwork for developing more effective treatments for infectious diseases.

Gold particles modified with chemical residues interact with immune cells. Developing a drug or vaccine requires a delicate balancing act with the immune system. On one hand, medications need to escape detection by the immune system in order to perform their function. But vaccinations — de-activated versions of a disease or virus — need to do the reverse. They prompt the immune system to create protective antibodies. But scientists are still stumped by how the immune system recognizes different particles, and how it chooses whether or not to react against them.