The authors next analyzed the light scattering profiles of growing and quiescent cells. While a culture of growing cells displayed a highly uniform light scattering profile, a culture of cells grown for 24 hours (and therefore post-diauxic shift) showed three distinct profiles. These profiles were assigned to cell populations designated R1, R2, and R3, with each group displaying a different light scattering profile (see figure). Strikingly, the R3 population showed a DNA fluorescence profile that was highly similar to that of purified quiescent cells. The authors went on to confirm that cell wall changes were responsible for the DNA fluorescence and light scattering profiles observed, both by repeating the experiments in the presence of a reducing agent to weaken cell wall integrity and by using a yeast strain carrying a mutation in a gene important for cell wall strengthening in quiescent cells.