TECHNOLOGY |
A microfluidics technique allows researchers to deliver certain kinds of molecules selectively into regions of a living cell. Using a technique developed previously, the researchers produce parallel and adjacent streams of different fluids that flow laminarly and mix only slowly by diffusion. If the streams contain membrane-permeable molecules, they will flow right through a cell placed in their path, thereby delivering one type of molecule to one part of the cell and another type to another part. In the experiment shown here (left), a red dye stains mitochondria in the upper half of a bovine capillary endothelial cell, while a green dye stains mitochondria in the lower half of the same cell. The entire cell is also treated with a DNA-staining dye that makes the nucleus blue. Two-and-a-half hours later (right), the mingled colors trace how the two populations of mitochondria have been moving and intermixing inside the cell.
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