The present invention, in one aspect, provides a culture vessel which includes a body having at least a first edge at least partially perimetrically bounding the body, and at least a first seal extending from the first edge. The first seal is breachable and fluid-tight, and disposed obliquely to the first edge so as to subtend an acute angle therewith. The first seal separates the body into first and second chambers. Advantageously, with the subject invention, a culture vessel is provided which allows for volume expansion in situ.