Claims
- 1. A method of harvesting platelets from a platelet-containing solution comprising:
- separating the platelet-containing solution into a supernatant layer and a sediment layer containing red cells; and
- passing the supernatant layer through a filter until red cells block the filter, said filter including a porous medium having zones of different density.
- 2. The method of claim 1 wherein passing the supernatant layer through the porous medium comprises passing platelet-rich plasma through the porous medium.
- 3. The method of claim 1 wherein said filter comprises a porous medium having a CWST greater than about 70 dynes/cm.
- 4. The method of claim 2 wherein passing the supernatant layer through a filter further comprises passing the supernatant layer through a filter having a flow area of about 3 cm.sup.2 to about 8 cm.sup.2.
- 5. The method of claim 1 wherein passing the supernatant layer through a filter further comprises passing the supernatant layer through a filter having a density range in an upstream portion from about 0.18 g/cc to about 0.23 g/cc, and a density range in the downstream portion from about 0.23 g/cc to about 0.40 g/cc.
- 6. The method of claim 5 wherein passing the supernatant layer through a porous medium having zones of different density comprises passing the supernatant layer through at least two zones of different density.
- 7. The method of claim 6 wherein passing the supernatant layer through zones of different density comprises passing the supernatant layer through zones of successively higher density.
- 8. The method of claim 7 wherein passing the supernatant layer through at least two zones of different density comprises passing the supernatant layer through an upstream zone including a density range from about 0.1 g/cc to about 0.2 g/cc, through an intermediate zone including a density range from about 0.20 g/cc to about 0.25 g/cc, and through a downstream zone including a density range from about 0.23 g/cc to about 0.40 g/cc.
- 9. A method for treating blood comprising:
- centrifuging blood to create a supernatant layer and a sediment layer; and
- passing the supernatant layer of the centrifuged blood through a porous medium until red blood cells block the porous medium, said filter including a porous medium having zones of different density.
- 10. The method of claim 9 further comprising collecting the supernatant layer passing through the porous medium.
Parent Case Info
This application is a continuation-in-part application of U.S. Ser. No. 07/609,574, filed Nov. 6, 1990, now issued U.S. Pat. No. 5,152,905 which is a continuation-in-part of U.S. Ser. No. 07/405,977, filed Sep. 12, 1989 (now abandoned); and of U.S. Ser. No. 07/609,654, filed Nov. 6, 1990, now issued U.S. Pat. No. 5,100,564.
US Referenced Citations (63)
Foreign Referenced Citations (10)
Number |
Date |
Country |
114281 |
Aug 1984 |
EPX |
370584 |
May 1990 |
EPX |
446713 |
Sep 1991 |
EPX |
455215 |
Nov 1991 |
EPX |
2735179 |
Feb 1978 |
DEX |
2511872 |
Mar 1983 |
FRX |
9104088 |
Apr 1991 |
WOX |
1501665 |
Feb 1978 |
GBX |
2017713 |
Oct 1979 |
GBX |
2231282 |
Nov 1990 |
GBX |
Continuation in Parts (2)
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Number |
Date |
Country |
Parent |
609574 |
Nov 1990 |
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Parent |
405977 |
Sep 1989 |
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