Serum separator system for centrifuge with piercable membrane

An assembly to be used in connection with a centrifuge, for separating and isolating lighter components from heavier components of blood mixtures, comprising:

• a first elongated barrel for holding a blood specimen, said barrel being open at its upper end and including a needle at its lower end for providing entry of said blood specimen;
• a container positioned in said barrel and slidable therein as a plunger, said container including a fluid opening at both its lower end and its upper end;
• means for selectively sealing said lower opening of said container depending on the direction of container movement in said barrel, said sealing means becoming closed when said container is pulled upwardly in the barrel such that a vacuum is created in said barrel, said sealing means becoming open when said container is pushed downwardly in the barrel allowing liquid to pass from said barrel, through said lower opening and into said container;
• filtration means located at the lower end of said container for permitting the passage of soluble components of said blood specimen from said barrel to said container, but preventing passage of insoluble components when the container is pushed into the barrel with said upper opening of said container open;
• and
• a locking means including a recessed step located around said container and a flexible oval-shaped flange located at said upper opening of said barrel, a portion of said oval flange positioned in an overlapping relationship with the path of said container within said barrel so that when said recessed step of said container aligns with said oval flange, said overlapping portion secures itself against said recessed step, thereby preventing movement of said container into said barrel, said oval-shaped flange transformable to a shape which is substantially similar to the cross section of said container, thereby disengaging said flange from said recessed step and allowing container movement within said barrel.

An assembly to be used in connection with a centrifuge, for separating and isolating lighter components from heavier components of blood mixtures, comprising:

• a first elongated barrel for holding a blood specimen, said barrel being open at its upper end and including a needle at its lower end for providing entry of said blood specimen, said barrel having a means defining a passageway comprising a first end in fluid communication with the inside of said barrel and a second end in fluid communication with the outside of said assembly when said sealing means passes said first end during extreme upward movement of said container, said first end of said passageway being located along said barrel such that said vacuum created during upward movement of said container in said barrel is equilibrated with the pressure outside said assembly just before said container is separated from said barrel, thus avoiding air turbulence within said barrel;
• a container positioned in said barrel and slidable therein as a plunger, said container including a fluid opening at both its lower end and its upper end;
• means for selectively sealing said lower opening of said container depending on the direction of container movement in said barrel, said sealing means becoming closed when said container is pulled upwardly in the barrel such that a vacuum is created in said barrel, said sealing means becoming open when said container is pushed downwardly in the barrel allowing liquid to pass from said barrel, through said lower opening and into said container;
• and
• filtration means located at the lower end of said container for permitting the passage of soluble components of said blood specimen from said barrel to said container, but preventing passage of insoluble components when the container is pushed into the barrel with said upper opening of said container open.

A method for separating and isolating the lighter components of a blood specimen from its heavier components comprising the steps of:

• providing a device having a barrel with an upper opening and means for selectively introducing said blood specimen, using a needle through a lower end of said barrel, said introducing means comprising a piercable membrane, a container acting as a fluid plunger slidable within said barrel between upper and lower positions, said container including a lower opening and an upper opening, one-way valve means disposed on said lower opening of said container between said container and said barrel for controlling fluid flow therebetween, said valve means operating in response to the direction of container movement within said barrel wherein upward container movement opens said valve and downward container movement closes said valve, and filter means disposed immediately above said one-way valve means within said fluid flow;
• lifting said container within said barrel such that said valve means closes, thereby creating a vacuum within said barrel;
• using said created vacuum within said barrel to draw in said blood specimen from a blood source;
• removing said needle from said membrane;
• centrifuging said barrel such that said container blood specimen separates into lighter and heavier fluid components, said lighter fluid components being located closer to said container than said heavier components;
• lowering said container into said lighter fluid components such that said valve means opens and said lighter fluid components flow past said filter means into said container;
• and
• lifting said container such that said valve means closes, thereby isolating said lighter components from said heavier components.