ITC-measured heat flow (μcal/s) released when wt phage λis titrated into LamB solution, triggering DNA ejection at different temperatures, in 10 mM MgCl2 Tris-buffer. (A) At temperatures below the intracapsid DNA transition (22 and 32°C), DP curve shows two exothermic peaks associated with two phage populations with fast (synchronized) and slow (desynchronized) DNA ejection dynamics. At temperatures above the intracapsid DNA transition (37 and 42°C), DP curve shows only one exothermic peak associated with one phage population with fast synchronized ejection dynamics. (B) DP curve for phage DNA ejection at 32°C (below DNA transition temperature) is fitted with deconvoluted skewed Gaussian curves, resolving peaks for both fast and slow ejection dynamics. (C) DP curve for phage DNA ejection at 37°C (above DNA transition temperature) fitted with skewed bimodal (deconvoluted) and unimodal Gaussian curves. Bimodal fit overlaps with unimodal fit, demonstrating that asymmetric unimodal Gaussian fit can be used to determine peak position and median time for ejection process above the DNA transition temperature, where one phage population with synchronized ejection dynamics is predominant. (D) Median time values derived from skewed Gaussian fit analysis for the DNA ejection process at five different temperatures (both bimodal and unimodal fits were made depending on the number of peaks). Error bars show the standard error (SE) of the width of Gaussian fit. Below the DNA transition temperature (22 and 32°C), two exothermic peaks are well resolved. Above the DNA transition temperature (37 and 42°C), deconvoluted peaks overlap and can be fitted with unimodal skewed Gaussian fit, as shown in (B).