Cell culture devices and related methods

A laboratory device, comprising:

• a receptacle having one or more sidewalls extending substantially orthogonally upward from a bottom wall;
• one or more limits surrounding the one or more sidewalls, the one or more limits extending a non-constant and shorter distance from the bottom wall relative to the one or more sidewalls;
• and
• a lid having a continuous skirt extending orthogonally downward from an upper plane thereof, a height of the skirt at a first edge or corner of the lid is minimal and a height of the skirt at an opposed second edge or corner of the lid is maximal,
• wherein the bottom wall lies in a substantially level plane when the receptacle rests on a level surface, and the upper plane of the lid lies in a plane that is parallel to the bottom wall when the skirt rests against the one or more limits, and
• wherein the bottom wall is tilted relative to the level surface when an underside of the receptacle is positioned on the upper plane of the lid as the skirt rests against the level surface.