US2587221A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pregnancy test
Assignee: Chicago Endocrine Research Co
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Filing: 1949-03-16
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Granted: 1952-02-26
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Expires: 1969-03-16
Abstract
No abstract record available.
Inventors
- 👤 Garwood C Richardson
- 👤 Gustav W Rapp
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:38
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/74; G01N33/743; Y; Y10; Y10T; Y10T436/00; Y10T436/20; Y10T436/200833
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
52 words
IN A METHOD FOR DETERMINING PREGNANCY THE STEPS WHICH COMPRISE, ALKALINIZING FEMALE URINE, EXTRACTING THE ALKALINE URINE WITH A WATER IMMISCIBLE ORGANIC SOLVENT, SEPARATING THE AQUEOUS PHASE OF THE EXTRACTED URINE FROM THE ORGANIC SOLVENT EXTRACT, ACIDIFYING THE EXTRACTED URINE, ADDING 2,4-DINITROPHENYLHYDRAZINE TO THE ACIDIFIED URINE, AND ALKALINIZING THE RESULTING REACTION MIXTURE.
Claim 2
Dependent Claim
52 words
IN A METHOD FOR DETERMINING PREGNANCY THE STEPS WHICH COMPRISE, ALKALINIZING FEMALE URINE, EXTRACTING THE ALKALINE URINE WITH A WATER IMMISCIBLE ORGANIC SOLVENT, SEPARATING THE AQUEOUS PHASE OF THE EXTRACTED URINE FROM THE ORGANIC SOLVENT EXTRACT, ACIDIFYING THE EXTRACTED URINE, ADDING 2,4-DINITROPHENYLHYDRAZINE TO THE ACIDIFIED URINE, AND ALKALINIZING THE RESULTING REACTION MIXTURE.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1955-02-25 | 1955-08-27 | 1956-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-02-25 | 1959-08-27 | 1960-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-02-25 | 1963-08-27 | 1964-02-26 | $7700.00 | Window Closed / Lapsed |