US3955928A
Expired / Lapsed
US
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Pregnancy test
Assignee: Individual
•
Filing: 1975-08-15
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Granted: 1976-05-11
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Expires: 1995-08-15
Abstract
Abstract A process for determining pregnancy wherein the concentration of estrogen steroids in the urine is evaluated by spectrophotometric measurement.
Inventors
- 👤 Hugh Yee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 23:51
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/74; G01N33/743; Y; Y10; Y10T; Y10T436/00; Y10T436/20; Y10T436/200833; Y10T436/203332
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
59 words
A process for determining pregnancy by measurement of the estrogens present in urine, comprising the steps of: a. separating the estrogen steroids from the urine; b. hydrolyzing the separated estrogen steroids; c. extracting the estrogen steroids from the urine; d. forming the estrogen steroid extract into chromogens; and e. evaluating the concentration of the estrogen steroids by spectrophotometric measurements.
Claim 2
Dependent Claim
59 words
A process for determining pregnancy by measurement of the estrogens present in urine, comprising the steps of: a. separating the estrogen steroids from the urine; b. hydrolyzing the separated estrogen steroids; c. extracting the estrogen steroids from the urine; d. forming the estrogen steroid extract into chromogens; and e. evaluating the concentration of the estrogen steroids by spectrophotometric measurements.
Claim 3
Dependent Claim
26 words
The process defined in claim 1 wherein the step of separating the estrogen steroids from the urine is accomplished by precipitation with ammonium sulfate and centrifugation.
Claim 4
Dependent Claim
34 words
The process of claim 1 wherein the step of separating the estrogen steroids from the urine is accomplished in a neutral ion-exchange resin chromotography column and then eluted from the resin column with methanol.
Claim 5
Dependent Claim
25 words
The process of claim 1 wherein the step of hydrolyzing the separated estrogen steroids is performed with an enzyme mixture of beta-glucuronidase and phenol sulfatase.
Claim 6
Dependent Claim
21 words
The process of claim 1 wherein the step of hydrolyzing the separated estrogen steroids is performed in an acetate buffered solution.
Claim 7
Dependent Claim
30 words
The process of claim 1 wherein the extracting of the estrogen steoids from the urine is effected with ethyl-ether, the ether then being evaporated to yield an estrogen steroid residue.
Claim 8
Dependent Claim
47 words
The process as defined in claim 1 wherein the step of evaluating the concentration of the estrogen steroids is performed by spectrophotometric measurement at wavelengths of the order of 520-550 nm and comparison of the absorbance values thereby obtained with those of estrogen standards of known concentrations.
Claim 9
Dependent Claim
36 words
The process of claim 1 wherein the step of separating the estrogen steroids from the urine is effected by solvent extraction with a 3:1 ratio ethy ether-ethanol solvent mixture of the urine sample with ammonium sulfate.
Claim 10
Dependent Claim
23 words
The process defined in claim 8 wherein after the chromogen forming there is included the further step of buffering with an EDTA-borate solution.
Claim 11
Dependent Claim
42 words
The process of claim 1 wherein the step of forming chromogens is accomplished by the reaction of the estrogen steroids by a coupling of the phenolic group of estrogen steroid molecules with a conjugating agent, followed by the further step of oxidation.
Claim 12
Dependent Claim
13 words
The process of claim 10 wherein the conjugating agent comprises 3-methyl-2-benzothiazolinone hydrazone hydrochloride.
Claim 13
Dependent Claim
11 words
The process of claim 10 wherein the conjugating agent comprises 4-aminoantipyrine.
Claim 14
Dependent Claim
17 words
The process defined in claim 10 wherein the further step of oxidation is accomplished with ceric salts.
Claim 15
Dependent Claim
23 words
The process defined in claim 10 wherein the further step of oxidation of the estrogen steroids is accomplished by treatent with ferric salts.
Claim 16
Dependent Claim
19 words
The process defined in claim 10 wherein the further step of oxidation is accomplished by treatment with ammonium persulfate.
References Cited (Backward Citations)
US3615229A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-05-11 | 1979-11-10 | 1980-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-05-11 | 1983-11-10 | 1984-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-05-11 | 1987-11-10 | 1988-05-11 | $7700.00 | Window Closed / Lapsed |