Claims
- 1. A method for enzymatically removing blood type-specific antigens from erythrocytes, comprising the following sequence of steps:
(a) titrating the pH of a native erythrocyte suspension to a conversion pH suitable for activity of a converting enzyme by adding a buffer solution having a pH at least one unit lower than the conversion pH; (b) adding an amount of converting enzyme effective in removing a blood-type specific antigen from the erythrocytes; (c) incubating the erythrocyte suspension containing the converting enzyme at a temperature and for a period of time sufficient to remove the blood type-specific antigen from the erythrocytes, thereby forming a converted erythrocyte suspension; (d) titrating the pH of the converted erythrocyte suspension to a physiologic pH by adding a buffer having a pH of 8-10; and (e) washing the erythrocytes to remove converting enzyme.
- 2. The method of claim 1 where the converting enzyme is coffee-bean α-galactosidase.
- 3. The method of claim 2 wherein the conversion pH is 5.4-5.8.
- 4. The method of claim 3 wherein the buffer solution used in step (a) has a pH of less than 3.5.
- 5. The method of claim 2 further comprising adding polyethylene glycol in step (b).
- 6. The method of claim 3 further comprising adding polyethylene glycol in step (b).
- 7. The method of claim 4 further comprising adding polyethylene glycol in step (b).
- 8. The method of claim 1 where the converting enzyme is a chicken liver N-acetylgalactosaminidase.
- 9. The method of claim 8 wherein the conversion pH is 5.4-7.0.
- 10. The method of claim 9 wherein the buffer solution used in step (a) has a pH of less than 3.5.
- 11. The method of claim 8, further comprising adding polyethylene glycol in step (b).
- 12. The method of claim 9, further comprising adding polyethylene glycol in step (b).
- 13. The method of claim 10, further comprising adding polyethylene glycol in step (b).
- 14. The method of claim 1 where the converting enzyme is an endo β-galactosidase of Flavobacterium keratolyticus.
- 15. The method of claim 14 wherein the conversion pH is 5.4-7/0.
- 16. The method of claim 15, wherein the buffer solution used in step (a) has a pH of less than ob 3.5.
- 17. The method of claim 14, further comprising adding polyethylene glycol in step (b).
- 18. The method of claim 15, further comprising adding polyethylene glycol in step (b).
- 19. The method of claim 16, further comprising adding polyethylene glycol in step (b).
Government Interests
[0001] This invention was made, at least in part, with Government support under Grant No. N00014-93-1-0364 from the Office of Naval Research and Development Command, such that the United States Government may have certain rights herein.
Continuations (1)
|
Number |
Date |
Country |
Parent |
08753212 |
Nov 1996 |
US |
Child |
09735400 |
Dec 2000 |
US |