US5135650A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chromatography stationary phase material for high performance liquid chromatography
Assignee: Bio Rad Laboratories Inc
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Filing: 1990-05-02
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Granted: 1992-08-04
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Expires: 2010-05-02
Abstract
Abstract Highly compressible chromatographic stationary phase particles such as agarose beads are made rigid to a degree suitable for use in HPLC, and nonporous to proteins by one of two procedures. The first involves shrinking the beads with the use of an organic solvent in which the agarose bead will neither dissolve nor swell to collapse the porosity, followed by crosslinking the bead surfaces inside the collapsed pores to fix the pores in their collapsed state. The second involves filling the pores (without shrinkage of the beads) with a polymerizable substance which grafts to the pore surface, and performing the graft polymerization. The invention also extends to rigid beads, which are rendered deformable to a limited degree by coating the surface with a polymer. Finally, porous rigid beads are rendered nonporous by polymerizing a polymerizable material inside the pores in the same manner as the porous compressible beads.
Inventors
- 👤 Stellan Hjerten
- 👤 Jia-Li Liao
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:46
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/28; B01J20/28054; B01J20/28095; B01J20/28097; B01J20/22; B01J20/26; B01J20/262; B01J20/265; B01J20/267; B01J20/281; B01J20/282; B01J20/285; B01J20/286; B01J20/30; B01J20/32; B01J20/3202; B01J20/3206; B01J20/3208; B01J20/3212; B01J20/3231; B01J20/3242; B01J20/3268; B01J20/3278
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
151 words
A method for converting agarose beads with pores filled with an aqueous medium and of sufficient porosity to be permeable to proteins, to beads of sufficiently low porosity to be substantially impermeable to proteins, said method comprising: (a) treating said agarose beads with a first organic solvent in which agarose is soluble but which promotes swelling of agarose, to weaken the agarose while retaining said agarose in the form of beads; (b) replacing substantially all of said first organic solvent and any remaining water in said agarose beads with a second organic solvent which neither dissolves nor swells the agarose to cause the pores of said agarose beads to at least partially collapse, thereby imparting to said beads a reduced porosity; (c) placing an agarose crosslinking agent inside the pores of said beads; and (d) causing said crosslinking agent to crosslink the agarose inside said pores to fix said reduced porosity.
Claim 2
Independent Claim
151 words
A method for converting agarose beads with pores filled with an aqueous medium and of sufficient porosity to be permeable to proteins, to beads of sufficiently low porosity to be substantially impermeable to proteins, said method comprising: (a) treating said agarose beads with a first organic solvent in which agarose is soluble but which promotes swelling of agarose, to weaken the agarose while retaining said agarose in the form of beads; (b) replacing substantially all of said first organic solvent and any remaining water in said agarose beads with a second organic solvent which neither dissolves nor swells the agarose to cause the pores of said agarose beads to at least partially collapse, thereby imparting to said beads a reduced porosity; (c) placing an agarose crosslinking agent inside the pores of said beads; and (d) causing said crosslinking agent to crosslink the agarose inside said pores to fix said reduced porosity.
Claim 3
Dependent Claim
25 words
A method in accordance with claim 1 in which said crosslinking agent is a member selected from the group consisting of epoxides, bisepoxides and trisepoxides.
Claim 4
Dependent Claim
27 words
A method in accordance with claim 1 in which said crosslinking agent is a member selected from the group consisting of 1,4-butanediol diglycidyl ether and γ-glycidoxypropyltrimethoxy silane.
Claim 5
Dependent Claim
22 words
A method in accordance with claim 1 in which said second organic solvent is one tending to avoid aggregation of agarose beads.
Claim 6
Dependent Claim
22 words
A method in accordance with claim 1 in which said first organic solvent is water-miscible, and miscible with said second organic solvent.
Claim 7
Dependent Claim
26 words
A method in accordance with claim 1 in which said agarose beads having an average bead diameter ranging from about 3 microns to about 300 microns.
Claim 8
Dependent Claim
26 words
A method in accordance with claim 1 in which said agarose beads having an average bead diameter ranging from about 10 microns to about 100 microns.
Claim 9
Dependent Claim
25 words
A method in accordance with claim 1 in which said agarose beads have an agarose concentration ranging from about 8% to about 20% by weight.
Claim 10
Dependent Claim
25 words
A method in accordance with claim 1 in which said agarose beads have an agarose concentration ranging from about 10% to about 15% by weight.
Claim 11
Dependent Claim
33 words
A method in accordance with claim 1 in which said reduced porosity is sufficiently reduced to render the agarose beads resulting from step (c) nonpermeable to proteins of molecular weight 12,000 and higher.
Claim 12
Dependent Claim
33 words
A method in accordance with claim 1 in which said reduced porosity is sufficiently reduced to render the agarose beads resulting from step (c) nonpermeable to proteins of molecular weight 10,000 and higher.
Claim 13
Dependent Claim
33 words
A method in accordance with claim 1 in which said reduced porosity is sufficiently reduced to render the agarose beads resulting from step (c) nonpermeable to proteins of molecular weight 3,000 and higher.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-08-04 | 1996-02-03 | 1996-08-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-04 | 2000-02-03 | 2000-08-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-04 | 2004-02-03 | 2004-08-04 | $7700.00 | Window Closed / Lapsed |