High recovery vial construction

A high recovery vial comprising, in combination:

• a tube having an upper end, a lower end, an internal passage extending from an open top between the upper end to the lower end, said passage having a side wall, said side wall being generally uniformly straight, constant diameter cylindrical wall and extending from the upper end to the lower end and defining a center axis of symmetry, the passage having a closure surface wall at the lower end, said closure surface wall being symmetrical about the center axis and defined by a cross sectional profile through the center axis, said profile consisting essentially of a first arcuate section connected from the cylindrical side wall to a straight planar section at an angle in the range of about 30° to 60° with the axis, to a center arcuate section aligned with the axis, said first arcuate section having a radius in the range of about 8.0 to 10.0 millimeters and said center arcuate section having a radius in the range of about 1.0 to 2.5 millimeters, said lower end having flat planar outside support surface transverse to the axis.