cap to be placed without interfering with another flask when the flasks are stacked a preferred embodiment of the invention incorporates the neck into the corner 140 to allow for more cell culture surface area since the neck and shoulders use less of the footprint area as a result access to the cell culture surface with pipettes or cell scrapers is not sacrificed due to the preferred corner location of the neck and cap for instance a 100 cm 2 version of the flask of this invention has a similar overall footprint as a standard 75 cm 2 flask although the truncated corner having a neck and cap located in the center of one side of the flask may integrally incorporate the entire neck of the flask into the molded piece a preferred embodiment fig1 b of the present invention incorporates a separate neck portion 130 for receiving a snap fit cap 132 one embodiment of the present invention may incorporate a neck 130 having parallel symmetric sides in a cylindrical shape an alternative embodiment flares the side surfaces of the neck from mouth to neck opening so that an increasing diameter accommodates the exterior draft surfaces 144 and 146 fig1 d the draft angles of the surfaces in turn facilitate fluid from being trapped in the corner shown in fig1 c is a partial cross sectional view of the flask shown in fig1 a the separate neck is bonded to the neck opening 131 in the truncated corner 140 by any number of methods including but not limited to solvent bonding ultrasonic welding or heat welding heat welding is preferred to establish a hermetic seal referring to fig3 b the neck 130 may be of any size or shape and should preferably be capable of blocking the entrance or.