Abstract: The invention provides a method for producing a multicellular spheroid comprising injecting a cell suspension into a gel. The invention also provides a method of producing a gel comprising one or more multicellular spheroids, the method comprising injecting a cell suspension into a gel, as well as a gel obtainable by the method. Also provided is a method of assessing the effect of an agent on the property of a cell selected from any of survival, growth, proliferation, differentiation, migration, morphology, signalling, metabolic activity, gene expression and cell-cell interaction, the method comprising (i) producing a multicellular spheroid or gel according to the method of the invention, or providing a gel according to the invention; and (ii) assessing the effect of the agent on the property of a cell in the multicellular spheroid.