US3640809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chemically hardened gelatin-separating medium for chromatography and ion exchange and method of making the same
Assignee: South African Inventions Development Corp
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Filing: 1968-12-10
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Granted: 1972-02-08
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Expires: 1988-12-10
Abstract
Abstract Selected gelatin, in particular the high molecular weight fraction obtained by fractionation with PEG is chemically hardened e.g. with tanning agents and used in a form of beads for exclusion chromatography and/or ion exchange or as a continuous body for electrophoresis. Ion exchange properties may be suppressed or enhanced as required by chemical treatment of the gelatin or by the choice of conditions during separation (pH, salt content). Ion-exchange properties are calibrated by electroosmosis.
Inventors
- 👤 Alfred Polson
- 👤 Woolf Katz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 17:32
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/281; B01J20/291; B01J20/22; G; G01; G01N; G01N30/00; G01N30/02; G01N30/50; B01J2220/00; B01J2220/50; B01J2220/54
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
21 words
A separating medium as claimed in claim 1 which is indispersable in water at temperatures at least up to 100* C.
Claim 2
Dependent Claim
45 words
A separating medium as claimed in claim 1 wherein the gelatin is selected with a high molecular weight in the sense of having an intrinsic viscosity of at least 0.9 deciliters per gram measured in 4 molar urea, saline, neutral pH prior to said hardening.
Claim 3
Dependent Claim
35 words
A separating medium as claimed in claim 1 wherein a gelatin is selected having a sedimentation coefficient in excess of 2.4 X 10 13 cm./sec./dyne, measured in 4 M urea, saline, prior to said hardening.
Claim 4
Dependent Claim
24 words
A separating medium as claimed in claim 1, wherein the anionic groups of the gelatin have been at least partly eliminated by said hardening.
Claim 5
Dependent Claim
24 words
A separating medium as claimed in claim 1, wherein the cationic groups of the gelatin have been at least partly eliminated by said hardening.
Claim 6
Dependent Claim
16 words
A separating medium as claimed in claim 1 wherein said gelatin has been hardened with formaldehyde.
Claim 7
Dependent Claim
17 words
A separating medium as claimed in claim 1 wherein said gelatin has been hardened by chromium tanning.
Claim 8
Dependent Claim
18 words
A separating medium as claimed in claim 8 wherein said gelatin has in addition been hardened with formaldehyde.
Claim 9
Dependent Claim
20 words
A separating medium as claimed in claim 1 wherein ion-exchange groups have been introduced into the gelatin by chemical reaction.
Claim 10
Dependent Claim
29 words
A separating medium as claimed in claim 1 wherein the gelatin employed constitutes a fraction of higher molecular weight obtained by a fractionation on the basis of molecular weight.
Claim 11
Dependent Claim
19 words
A separating medium as claimed in claim 11 wherein the gelatin has been subjected to fractionation with polyethylene glycol.
Claim 12
Dependent Claim
29 words
A separating medium as claimed in claim 1 in a form suitable for chromatography and having a ratio of surface area to volume of at least 10 cm. 1.
Claim 13
Dependent Claim
13 words
A separating medium as claimed in claim 13 in the form of beads.
Claim 14
Dependent Claim
17 words
A separating medium as claimed in claim 14 wherein the bead diameter is from 300 microns downwards.
Claim 15
Dependent Claim
15 words
A separating medium as claimed in claim 1 having ion-exchange properties calibrated by electro osmosis.
Claim 16
Dependent Claim
14 words
A separating medium as claimed in claim 1 when incorporated in a chromatographic apparatus.
Claim 17
Dependent Claim
76 words
A calibrated separating medium of a macromolecular character for chemical separations by chromatography comprising a chemically hardened gelatin medium in a form suitable for a chromatographic separating process, said medium being indispersable in water at temperatures at least above 7* C. and permeable to the flow therethrough of a chromatographic mobile phase and having ion-exchange characteristics which are calibrated by forming a membrane and carrying out electro-osmosis through said membrane at a plurality of pH values.
Claim 18
Independent Claim
71 words
A method of preparing a separating medium which comprises the step of transforming a suitable selected gelatin into a porous form having pores constituting flow passages and physically adapted as a separating medium for chromatography, permeable to the flow therethrough of a chromatographic mobile phase, and a chemical step of hardening the gelatin and insolubilizing it in the sense of rendering it indispersable in water above a temperature of 7* C.
Claim 19
Dependent Claim
17 words
A method as claimed in claim 19 wherein said hardening is carried out with a tanning agent.
Claim 20
Dependent Claim
15 words
A method as claimed in claim 20 wherein formaldehyde is employed as a tanning agent.
Claim 21
Dependent Claim
17 words
A method as claimed in claim 20 wherein a chromium-tanning composition is used as a tanning agent.
Claim 22
Dependent Claim
18 words
A method as claimed in claim 19 wherein the gelatin is first gelled and then subjected to hardening.
Claim 23
Dependent Claim
46 words
A method as claimed in claim 19 for producing the medium in the form of beads wherein the gelatin is dissolved in aqueous medium, emulsified with a substantially nonpolar medium and in the presence of an emulsifying agent, cooled with stirring and subjected to emulsion breaking.
Claim 24
Dependent Claim
20 words
A method as claimed in claim 24 wherein chemical hardening of the gelatin is carried out prior to the cooling.
Claim 25
Dependent Claim
22 words
A method as claimed in claim 24 wherein chemical hardening of the gelatin is carried out after the emulsion has been broken.
Claim 26
Dependent Claim
28 words
A method as claimed in claim 19 including the step of fractionating the gelatin on a molecular weight basis and recovering a fraction of increased average molecular weight.
Claim 27
Dependent Claim
18 words
A method as claimed in claim 19 including the step of adding ion-exchange groups to the gelatin molecules.
Claim 28
Dependent Claim
110 words
A fractionating process which comprises introducing a mixture to be fractionated into a separating medium of a macromolecular character for chemical separations by chromatography, said medium being chemically hardened gelatin in a form suitable for a chromatographic-separating process and being indispersable in water at temperatures at least above 7* C., and permeable to the flow therethrough of a chromatographic mobile phase, bringing about movement of a component of the mixture through the separating medium relative to at least one other component of the mixture at least in part by percolation of a liquid through said medium, and recovering at least one of said components separately from the other said component.
Claim 29
Dependent Claim
25 words
A process as claimed in claim 29 which comprises bringing about said movement by percolation of a liquid through a bed of the separating medium.
Claim 30
Dependent Claim
14 words
A process as claimed in claim 30 carried out by way of exclusion chromatography.
Claim 31
Dependent Claim
31 words
A process as claimed in claim 29 which comprises adjusting conditions of separating at least in part for ion exchange to take place as at least one factor determining the fractionation.
Claim 32
Dependent Claim
11 words
Substances whenever fractionated by a process as claimed in claim 29.
Claim 33
Dependent Claim
15 words
A process as claimed in claim 29 further comprising bringing about said movement by electrophoresis.
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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) | 1975-02-07 | 1975-08-09 | 1976-02-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-02-07 | 1979-08-09 | 1980-02-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-02-07 | 1983-08-09 | 1984-02-08 | $7700.00 | Window Closed / Lapsed |