US4415668A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cell culture
Assignee: Harvard University
•
Filing: 1981-04-20
•
Granted: 1983-11-15
•
Expires: 2001-04-20
Abstract
Abstract Improved cell culture microcarriers having controlled amphipathic (hydrophobic and polar) properties and controlled positive charge capacities, which make these microcarriers controllable in size in aqueous or non-aqueous environments and which produce outstanding growth of anchorage-dependent cells, and methods for their use.
Inventors
- 👤 Don L. Siegel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 21:14
CPC Classifications
C; C12; C12N; C12N5/00; C12N5/0068; C12N5/0075; C12N2533/00; C12N2533/70
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
134 words
The method of growing anchorage-dependent cells in microcarrier cell culture and preparation for examination in a non-aqueous organic solvent environment comprising growing cells in aqueous environment on microcarriers comprising polymeric support material having reactive chemical moieties thereon selected from the group consisting of hydroxyl and amide moieties and having bonded thereto hydrophobic chemical moieties selected from the group consisting of hydroxyethyl, hydroxypropyl and hydroxyalkoxypropyl moieties and bonded thereto an amount of positively charged chemical moieties to provide an exchange capacity within the range of between about 0.1 and about 4.5 meq/gram of dry untreated polymeric support material, staining and transferring said microcarriers bearing said cells from said aqueous cell growth environment to a non-aqueous organic solvent environment without shrinkage of said microcarriers, and examining the unshrunk microcarriers bearing said cells previously subjected to staining.
Claim 2
Independent Claim
134 words
The method of growing anchorage-dependent cells in microcarrier cell culture and preparation for examination in a non-aqueous organic solvent environment comprising growing cells in aqueous environment on microcarriers comprising polymeric support material having reactive chemical moieties thereon selected from the group consisting of hydroxyl and amide moieties and having bonded thereto hydrophobic chemical moieties selected from the group consisting of hydroxyethyl, hydroxypropyl and hydroxyalkoxypropyl moieties and bonded thereto an amount of positively charged chemical moieties to provide an exchange capacity within the range of between about 0.1 and about 4.5 meq/gram of dry untreated polymeric support material, staining and transferring said microcarriers bearing said cells from said aqueous cell growth environment to a non-aqueous organic solvent environment without shrinkage of said microcarriers, and examining the unshrunk microcarriers bearing said cells previously subjected to staining.
Claim 3
Dependent Claim
19 words
The method of claim 1, wherein said polymeric support material comprises a cross-linked polysaccharide having reactive hydroxyl moieties thereon.
Claim 4
Dependent Claim
13 words
The method of claim 2, wherein said hydrophobic chemical moieties comprise hydroxypropyl moieties.
Claim 5
Dependent Claim
18 words
The method of claim 2, wherein all of said reactive hydroxyl moieties have bonded thereto a hydroxypropyl moiety.
Claim 6
Dependent Claim
11 words
The method of claim 3, wherein said polysaccharide comprises cross-linked dextran.
Claim 7
Dependent Claim
17 words
The method of claim 2, wherein said positively charged chemical moieties comprise teritary or quaternary amine moieties.
References Cited (Backward Citations)
US4036693A
Cited
US4189534A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-11-14 | 1987-05-16 | 1987-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-11-14 | 1991-05-16 | 1991-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-11-14 | 1995-05-16 | 1995-11-15 | $7700.00 | Window Closed / Lapsed |