<prompt> Robert Koch assistant advised him to use agar instead of gelatine for solidifying culture media for cultivation of bacteria as -Agar has more nutritionGelatin melts at 37CGelatin is not easily availableAgar is cheaper  <response>: Agar is preferred to gelatin as a solidifying agent in culture media.This is because gelatin melts at relatively low temperature 35o C, while agar melts at around 85 C.Therefore, when gelatin is incubated at the normal temperature for bacterial growth, i e. at 37 C, it melts, while agar remains solid. 