A cell separation set for separating blood components, having a cell separation chamber with a first entry section having a wall with an outwardly flared curve, the entry section having an axial length and an inmost maximum diameter perpendicular to the axial length, the axial length being greater than the inmost maximum diameter. The cell separation chamber further comprises a separation section having a wall comprising an inward curve. A transition section between the entry section and the separation section has a wall comprising a second inward curve, the second inward curve being different from said first inward curve. The first curve may be tangent to the second curve at a first junction between the first and second curves and the second curve may be tangent to the third curve at a second junction between the second and third curves.
