To maximize the acquisition rate for micronuclei formation assays, a large-chip CCD camera is preferable to the standard-chip size. With a 2,048 x 2,048 pixel array, the large-chip camera acquires a field of view approximately four times that of the standard-chip camera (Table 1 and Figure 1).
Consequently, fewer fields of view are required to obtain the desired cell count. In addition, capture rates with the large-chip camera configuration are significantly more rapid than with the standard-chip camera in place. Both of these factors contribute to an increased speed of acquisition.
This is illustrated using dose-response assays with etoposide and mitomycin C as test compounds, with the online cell-count threshold set to 1,000. The number of fields imaged per well to achieve the threshold ranged from 1 to 34 using the standard-chip CCD cameras and 1 to 16 using the large-chip CCD camera.
Use of the large-chip camera reduced plate acquisition times by ~50% compared to those achieved with the standard-chip camera under comparable conditions (Table 1).