Selection method and apparatus

A method and an apparatus for selecting a cultured cell colony or a cultured single cell having a desired characteristic are disclosed. The method includes providing a plurality of cultured cell colonies or cultured single cells in a common culture space. The cell colonies or single cells are heterogeneous in respect of the desired characteristic. A treatment is applied to the cell colonies or to the single cells, while the cell colonies or the single cells are in the common culture space. The treatment elicits a change in a function of a cellular component of those cell colonies or single cells which have the desired characteristic. Individual ones of the cell colonies or of the single cells are then assessed, in the common culture space, for a marker of the change in the function. The method also comprises selecting at least one but not all of the cell colonies or of the single cells. The selection takes account of the assessment for the marker to determine expected possession of the desired characteristic. Each selected cell colony or single cell is expected to have the desired characteristic on the basis of the assessment. The method also includes providing an indication of the spatial position of at least one of the cell colonies or of the single cells that are selected.