The concept of using nanoparticles as a local sensor or probe enables important developments in medicine, molecular and cellular biology. To observe the entrance process of a particle into a cell in real time, in 3D and without perturbation of the biological specimen is a dream of many life science researchers.

Existing technologies such as epifluorescence, TIRF, LSM and video particle tracking have several drawbacks. Labeling is time consuming and causes perturbation in single molecule experiments. The best resolution in confocal microscopy (CLSM) is ~300nm in the X & Y and ~500nm in the Z axis.

Fluorescence is not label free and has poor performance for processes occurring on cell membranes. TIRF measures only the first 200nm from the surface of the cell and gives no access to the whole cell volume. Particle tracking by video microscopy is only a 2D technique with best resolution of 15nm.

What kind of tool is needed to fulfill the dream?

The answer is a live cell imaging technique with high temporal and spatial resolution applied to non labeled nanoparticles. JPK Instruments starts it's new product line with the

• NanoTracker™ - optical tweezers and 3D particle tracking system for live cell imaging at a new level