How will you calculate the length of the S period.

Explanation

A Culture of animal cells in which the cell cycles were asynchronous was incubated with 3H-Thymidine for 10 minutes. Autoradiography showed that 50% of the cells were labelled. If the cell cycle time (generation time) was 16 hrs how long was the period?
Length of the S period = Fraction of cells in DNA replication `times`generation time
Length of the S period = 0.5 `times` 16 hours = 8 hours