Self-contained swab cartridge apparatus for detecting occult blood
US4562043A · kind A · utility
Inventors
Key dates
| Filing date | Sep 9, 1983 |
| Grant date | Dec 31, 1985 |
| Priority date | — |
| Expiry date | Sep 9, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S435/81
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A tubular test device for testing occult blood in fecal matter using hydrogen peroxide in an ampoule and 3,3',5,5'-tetramethylbenzidine as the chromogen dissolved in chloroform to impregnate a cellulosic pledget which, when dried, is substantially colorless and is introduced adjacent a sampling swab into the device to lie adjacent the ampoule containing dilute hydrogen peroxide and a wetting agent. A special conditioning pre-coating for the pledget before impregnation with liquid chromogen in chloroform is provided consisting of hydroxyethylcellulose dissolved in an aqueous non-volatile acid buffer such as citric acid and sodium citrate to maintain a pH of 5-7, and then dried. The swab takes a sample of fecal matter. A cap is placed over the swab. The ampoule is broken. If fecal blood is present the hydrogen peroxide passes to the pledget aided by capillary action to create an intense green coloration in the cap very rapidly if the pledget is in the cap above the sampling swab and very slowly if the pledget is below the sampling swab. The color developed for a positive test is exceptionally long-lasting in the cap portion when 6-methoxyquinoline is added to the chromogen in chlorof…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.