A method for picking a colony of cells, the method comprising either the steps of (a) providing a suspension comprising cells and semi-solid medium in a sample container, the sample container having a substantially flat bottom wall, (b) centrifuging the sample container such that, after centrifugation, substantially all cells are positioned at the bottom wall, (c) determining and recording the position of one or more cells located within at least one predetermined region at the bottom wall, (d) incubating the sample container under conditions suitable for the growth of colonies of cells, (e) determining and recording the area occupied by one or more colonies of cells, the one or more colonies of cells being located within the at least one predetermined region at the bottom wall, and (f) selecting and picking at least one of the one or more colonies of cells occupying the area or areas determined and recorded in (e), and (g) optionally, inferring that a colony of cells selected and picked in (f) is monoclonal if the position of not less and not more than one cell, as determined and recorded in (c), is located within the area determined and recorded in (e) as the area occupied by the colony of cells selected and picked in (f); or the steps of (a') providing a suspension comprising cells and semi-solid medium in a sample container, the sample container having a substantially flat bottom wall, (b') centrifuging the sample container such that, after centrifugation, substantially all cells are positioned at the bottom wall, (c') determining and recording the position of one or more cells located within at least one predetermined region at the bottom wall, (d') incubating the sample container under conditions suitable for the growth of colonies of cells, (e') determining and recording the area occupied by one or more colonies of cells, the one or more colonies of cells being located within the at least one predetermined region at the bottom wall, (f') inferring that a colony of cells is monoclonal if the position of not less and not more than one cell, as determined and recorded in (c'), is located within the area determined and recorded in (e') as the area occupied by the colony of cells, and (g') selecting and picking at least one monoclonal colony of cells. (a) providing a suspension comprising cells and semi-solid medium in a sample container, the sample container having a substantially flat bottom wall, (b) centrifuging the sample container such that, after centrifugation, substantially all cells are positioned at the bottom wall, (c) determining and recording the position of one or more cells located within at least one predetermined region at the bottom wall, (d) incubating the sample container under conditions suitable for the growth of colonies of cells, (e) determining and recording the area occupied by one or more colonies of cells, the one or more colonies of cells being located within the at least one predetermined region at the bottom wall, and (f) selecting and picking at least one of the one or more colonies of cells occupying the area or areas determined and recorded in (e), and (g) optionally, inferring that a colony of cells selected and picked in (f) is monoclonal if the position of not less and not more than one cell, as determined and recorded in (c), is located within the area determined and recorded in (e) as the area occupied by the colony of cells selected and picked in (f); (a') providing a suspension comprising cells and semi-solid medium in a sample container, the sample container having a substantially flat bottom wall, (b') centrifuging the sample container such that, after centrifugation, substantially all cells are positioned at the bottom wall, (c') determining and recording the position of one or more cells located within at least one predetermined region at the bottom wall, (d') incubating the sample container under conditions suitable for the growth of colonies of cells, (e') determining and recording the area occupied by one or more colonies of cells, the one or more colonies of cells being located within the at least one predetermined region at the bottom wall, (f') inferring that a colony of cells is monoclonal if the position of not less and not more than one cell, as determined and recorded in (c'), is located within the area determined and recorded in (e') as the area occupied by the colony of cells, and (g') selecting and picking at least one monoclonal colony of cells.