ABSTRACT
A safer form of trapping was demonstrated by Ashkin and colleagues in late 1987 in which an infrared laser was used to trap cells without damaging them [20]. It is also notable as it makes use of a dualbeam optical tweezers for the first time (although this technique had been used in a levitation experiment previously [21]). The use of infrared beams is of key importance in biological experiments and nearly all experiments in the biological arena make use of such wavelengths.
