I noticed that the bottle only has white light to describe its surface and shape, it's ok. But maybe with some hints of red reflection from the blood (specially in the tube), or a little bit of dirt on the glass could make it look more finished.
About the light on the background, you know that some silent films were toned with orange and blue colors, like Nosferatu. Why not make the background in a rusty ocre or blue? This way you add some extra color to the image and it's a direct reference to the film also. This is just an idea, maybe is not worth at all!