Device for separating components of a fluid sample

Abstract

A device and method for separating heavier and lighter fractions of a fluid sample. The device includes a flexible collapsible inner container disposed within a substantially rigid outer container. A closure seals the open top end of the outer container. A filter assembly is sealingly mounted to the open top end of the inner container. The filter assembly includes a filter that permits lighter fractions to pass therethrough, while substantially blocking the heavier fractions. The filter assembly further includes a filter support having a slit valve registered with the filter. The slit valve opens in response to fluid pressure created by the lighter fractions for permitting the lighter fractions to flow therethrough. A fluid sample is delivered to the inner container and the device is subjected to centrifugation whereby the centrifugal load causes the filter assembly to move toward the bottom end of the outer container and thereby enable the lighter fraction of the fluid sample to flow through the slit valve and into the space between the inner and outer containers. The slit valve closes upon termination of the centrifugal load such that separation between the heavier and lighter fractions of the fluid sample are maintained.