When 5% sheep blood is added to nutrient agar and heated at 50°c ,blood agar is obtained. When 5% sheep blood is added to nutrient agar and heated at 70°c ,we get chocolate agar. Basically chocolate agar is lysed blood agar.
Yes ,contents of both blood agar and chocolate agar is same but the heating temperature is varying.
In chocolate agar RBCs will be lysed and the content of RBCs will be released changing the colour of the medium to brown