Claims
- 1. A filter unit for a blood-derived suspension containing both leukocytes and erythrocytes, said unit having a filter for removing leukocytes from said suspension, said filter including a plurality of layers all capable of passing erythrocytes, at least two of said layers being nitrocellulose membranes, wherein said nitrocellulose membranes include at least one nitrocellulose membrane having a pore size of 5-15 microns blocking said leukocytes while passing said erythrocytes and at least two of said layers being non-woven fibrous media.
- 2. A filter unit according to claim 1, and wherein at least one of said plurality of layers comprises a non-woven polymer fiber which constitutes a pre-filter.
- 3. A filter unit according to claim 2, and wherein one of said plurality of layers includes a plurality of nitrocellulose membranes interspersed by non-woven polymer fiber spacers.
- 4. A filter unit according to claim 3, wherein said nitrocellulose membranes includes a nitrocellulous membrane which is chemically modified by a surface grafting reaction while in contact with a monomer.
- 5. A filter unit according to claim 2, wherein said nitrocellulose membranes includes a nitrocellulous membrane which is chemically modified by a surface grafting reaction while in contact with a monomer.
- 6. A filter unit according to claim 1, and wherein one of said plurality of layers includes a plurality of nitrocellulose membranes interspersed by non-woven polymer fiber spacers.
- 7. A filter unit according to claim 6, wherein said nitrocellulose membranes includes a nitrocellulous membrane which is chemically modified by a surface grafting reaction while in contact with a monomer.
- 8. A filter unit according to claim 1, wherein said nitrocellulose membranes includes a nitrocellulous membrane which is chemically modified by a surface grafting reaction while in contact with a monomer.
Parent Case Info
This is a division of application 08/512,446 filed Aug. 8, 1995, now U.S. Pat. No. 5,707,526, which is a continuation-in-part of PCT/US94/01413 filed Feb. 8, 1994.
US Referenced Citations (21)
Foreign Referenced Citations (4)
Number |
Date |
Country |
155003 |
Sep 1985 |
EPX |
406485 |
Jan 1991 |
EPX |
408462 |
Jan 1991 |
EPX |
8902304 |
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WOX |
Divisions (1)
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Number |
Date |
Country |
Parent |
512446 |
Aug 1995 |
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