Fig. 3.

Different conditioned medium experimental procedures. 1) A porous membrane barrier prevents direct contact between the donor and acceptor cultures, allowing only secreted factors of a particular size in the medium to pass between the two compartments 2) Medium from the donor culture is collected and a naïve acceptor culture is incubated in the conditioned medium 3) Before applying the medium from the donor culture to the acceptor culture, components of the conditioned medium are extracted or concentrated 4) The donor culture co-express protein labelled with one of two complimentary fragments that luminesce when in close proximity with one another, which is dependent on self-association of at least two proteins labelled with one of each fragment. Application of conditioned medium obtained from the donor culture onto the acceptor culture will result in bioluminescence in acceptor cells only if the luminescent aggregate species are taken up by the acceptor culture.