Can you drive organoid orientation (inward vs outward)?

Yes. The orientation can be triggered by the use or lack thereof of ECM. Without the use of an ECM; the organoids will have a higher outward oriented ratio. You can find a protocol here https://pubmed.ncbi.nlm.nih.gov/30811997/; where cells were first embedded in ECM gel and afterwards ECM was dissociated; and free organoids were re-seeded in suspension without an ECM. * Please note that we have not tested this method in our labs and thus cannot guarantee it.