Tests made by people, for people.
The Art of Dry Chemistry
Dry chemistry test strip technology has evolved from simple litmus paper into a highly advanced technology during the last 50 years. It converts the labor-intensive, liquid laboratory test kits into simple, convenient, dip-and-read tests with results in seconds, taking the practice of diagnostic monitoring to a whole new level.
For example, a 45 second blood sugar test using a single drop of blood was not envisioned possible 40 years ago, but is now an everyday routine for diabetic patients. The accuracy and precision of those blood tests is not less than those performed in the laboratory using liquid reagent kits; and if made correctly, is even more precise with less user error.
Scientists at Sevillian Laboratories have been involved in the development of dry chemistry reagent systems for over a decade, specifically in the development of whole blood tests, urine reagent strips, saliva-based tests, and milk-based tests. We have coauthored 15 patents and others pending in the chemical testing of various analytes. These same technologies have laid the groundwork for the unique formulations and test strips that Sevillian supplies today.
Simple...
yet not so simple.
The basic principle of dry chemistry reagent technology is, in fact, very straightforward. It involves a simple process of impregnating liquid reagents into an absorbent material and drying it in an oven. A novice can easily develop a working prototype in three months, yet it may take them another three years to perfect the test to the desired performance characteristics. The most common problems one may encounter in test strip development are:
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Lack of thermal stability.
The strip becomes unstable and requires refrigeration or freezing for long term storage.
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Uneven color development.
The strip develops a patchy color pattern, which is often difficult to read and interpret.
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Limited quantitation range.
The strip has narrow quantitation range. It either lacks the sensitivity for detection of critically low levels of analyte, or is unable to differentiate high levels of analyte. In either case, it makes the test strip less effective and could provide a false sense of security in certain applications.
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Interferences.
The test strip reaction may be interfered by substances present in the test sample, thus causing a false positive or false negative reaction. In our tests, any non-specific activity or chemical interference is typically negated with a unique combination of masking agents. In the testing of biological fluids, elimination of potential interferences may become a major roadblock for some in the development of the test.