US4241174A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Interferon assay
Assignee: Roche Diagnostics Corp
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Filing: 1978-11-24
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Granted: 1980-12-23
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Expires: 1998-11-24
Abstract
Abstract A rapid cytopathic effect inhibition assay for interferon is disclosed. The assay can be completed in about 16 hours or less, allowing its use to assist in clinical diagnosis of viral infections and also, in monitoring the production and purification of interferon whether leukocyte or fibroblast.
Inventors
- 👤 Philip C. Familletti
- 👤 Sidney Pestka
- 👤 Sara Rubinstein
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 14:32
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/5005; C; C12; C12Q; C12Q1/00; C12Q1/70; Y; Y10; Y10S; Y10S435/00; Y10S435/811
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
188 words
An improved assay for interferon comprising the following steps in combination: a. contacting a serially diluted and segregated interferon containing sample in the presence of a cell support medium with a viable cell line preparation in the form of a cell suspension, said cell line known to be sensitive to the interferon type to be assayed, so as to form an interferon-cell line mixture in the form of a suspension; b. allowing said interferon-cell line mixture to incubate from 0 to 1 hour; c. adding a challenge virus preparation to each of said segregated, serially diluted interferon-cell line mixtures and allowing the resulting mixtures to incubate from about 12 to 18 hours; d. providing a virus control mixture comprising said viable cell line preparation and said challenge virus preparation, and a cell control comprising said viable cell line preparation; e. reading said assay mixtures when the said virus control mixture shows 100% cytopathic effect, whereby the titer of interferon in said sample is determined as the reciprocal of the dilution of the mixture showing a 50% reduction in cytopathic effect as compared to the virus and cell controls.
Claim 2
Dependent Claim
188 words
An improved assay for interferon comprising the following steps in combination: a. contacting a serially diluted and segregated interferon containing sample in the presence of a cell support medium with a viable cell line preparation in the form of a cell suspension, said cell line known to be sensitive to the interferon type to be assayed, so as to form an interferon-cell line mixture in the form of a suspension; b. allowing said interferon-cell line mixture to incubate from 0 to 1 hour; c. adding a challenge virus preparation to each of said segregated, serially diluted interferon-cell line mixtures and allowing the resulting mixtures to incubate from about 12 to 18 hours; d. providing a virus control mixture comprising said viable cell line preparation and said challenge virus preparation, and a cell control comprising said viable cell line preparation; e. reading said assay mixtures when the said virus control mixture shows 100% cytopathic effect, whereby the titer of interferon in said sample is determined as the reciprocal of the dilution of the mixture showing a 50% reduction in cytopathic effect as compared to the virus and cell controls.
Claim 3
Dependent Claim
18 words
The assay of claim 1 wherein said interferon containing sample consists of human leukocyte or human fibroblast interferon.
Claim 4
Dependent Claim
22 words
The assay of claim 2 wherein said cell line consists of bovine kidney cells and said challenge virus is vesicular stomatitis virus.
Claim 5
Dependent Claim
16 words
The assay of claim 3 wherein said assay is read after staining of the cell preparations.
Claim 6
Dependent Claim
14 words
The assay of claim 4 wherein the dye-fixative solution is crystal violet in methanol.
Claim 7
Dependent Claim
20 words
The assay of claim 1 wherein the said incubation steps are carried out at a temperature of about 37° C.
References Cited (Backward Citations)
US3910824A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-23 | 1984-06-23 | 1984-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-23 | 1988-06-23 | 1988-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-23 | 1992-06-23 | 1992-12-23 | $7700.00 | Window Closed / Lapsed |