Evening /out/casts,

With the upcoming semester I am looking for a new bag. I am finishing premed courses while working in a research lab, so I am trying to find a large, durable messenger bag to accommodate everything I carry all day. Any recommendations? I wouldn't be opposed to a larger bag, like a canvas duffel, but something that is easy to transport and store is ideal.

Pic related is what I currently own, it's ok for a laptop wires and maybe a notebook, but that's about it.