Some very early testing of fluorescence imaging in our optical tweezers instrument. A 10 kb long piece of DNA (ca 3 um long when stretched) is held between two optically trapped microspheres. The DNA is coated with a fluorescent dye (SYBR-gold) which is exited by a 488 nm blue laser and the fluorescence signal is [...]

I’m testing an EMCCD camera. This is a video of fluorescently labeled DNA through a 100x epi-fluorescence microscope. Or you can try a slightly better quality wmv-download (82 Mb) Once we’ve had time to practice some more, it should look much cooler, something like these DNA-curtains, or DNA-ejection from bacteriophage lambda. But it’s a start. Also [...]

A ~48 000 base-pair long (ca 16 um) piece of DNA is stretched between two optically trapped ca 2 um diameter polystyrene beads. Bright-field real-time view through a 100x microscope. Scale-bar in microns on the right.

Some promising results yesterday with trying to stretch DNA molecules. The molecule is attached between two microspheres, and we are actively moving the smaller sphere while the force acting on the bigger sphere is being measured. The image and video shows the view through a 100x microscope objective on the optical tweezers instrument I am [...]