Automated counting of cytolytic plaques for plaque formation assay in large format microplates

Cytolytic plaques are formed after a confluent monolayer of host cells are infected with the target viral particles, causing the cells to lyse.  After a specific time duration, the viral infection can generate large openings, where the contrast can be enhanced by staining the host cells with crystal violet.  Typically, these openings are manually counted with the naked eye.  Utilizing the Celigo Image Cytometer, the cytolytic plaques can be automatically imaged and counted in less than 5 min/plate using bright field.  Below are examples of the whole well and zoomed-in bright field images of cytotolytic plaques, as well as the counted image showing accurate identification of the plaques.

cytolytic plaque formation assay

Whole well and zoomed-in bright field images of cytolytic plaques formed in a 6-well plate.  The plaques were directly counted in the Celigo software, where the counted image showed accurate identification of the plaques.

plate view of the cytolytic plaques

Plate view of the cytolytic plaques with bright field, pseudo-filled color, and heat-map view in 24-well plates

The Celigo Image Cytometer automates viral titer assays: