pubmed-article:18770670 | pubmed:abstractText | One or more lasers are the source of illumination in the majority of fluorescence flow cytometers now in use. A typical laser emits a beam on the order of 1 mm in diameter. For efficient utilization this beam must be shaped and focused to a smaller size to illuminate the cell stream passing through the interrogation point. This unit discusses spot size requirements and the methods by which optimal spot size is achieved. | lld:pubmed |