we had cultured EB of mouse for 4days . Then we were going to let them attach to plate treated by gelatin, but 2days later ,EB still floated in the medium. Now we want to know this reason.???

maybe due to short enough serum or nutrient?

when we culture our embryonic bodies from mouse, we treat them for upwards of 5 to 7 days. during this time, they move from being a monolayer (ES cells) to floating culture. as the ES cells start to differentiate and form the germ layers (endo, ecto, mesoderm) - i am unaware of a protocol that utilizes them other than in a floating culture.