Phadebas

Phadebas is a synthetic biochemical substrate used for both qualitative and quantitative assessment of the α-amylase enzyme. Its active component is DSM-P, microspheres in which a blue dye has been chemically bound. When the substrate is digested by the amylase enzyme in solution, it releases that blue dye at a rate proportional to the quantity of the enzyme present. It is used in a range of applications from quality control tests for food & beverages to detection of saliva stains in forensic investigations.^[1]

History

The "Phadebas Amylase Test" (PAT) was the first product developed by Pharmacia Diagnostics and was launched in 1970.^[2] The name Phadebas is an abbreviation of Pharmacia Diagnostics Biologically Active Substances. In the 70’s PAT was used in hospitals world wide as an in vitro diagnostics test for acute pancreatitis but the application was later outrivaled by automatic analysis systems. PAT is no longer marketed for the IVD-market and no longer upholds its EC-certificate. Even though the original application has vanished the product is still used as a colouring agent in some clinical assays.^[3] Phadebas does not play an active role in the later diagnosis in these assays. The semi-manual method of Phadebas proved to function in other applications outside of the IVD-market. The method was up taken by forensic laboratories and by the food and chemical industry. In 2005 the company was acquired by Magle Life Sciences and in 2007, Phadebas Forensic was launched as a first diversification within the product family. Three years later, Phadebas Honey Diastase Test was launched resulting in totally eight products in the Phadebas portfolio.

Applications

Phadebas is used in a wide range of applications from quality control tests for food & beverages to detection of saliva stains in forensic investigation.

Research and Quality

PAT is used for accurately determining α-amylase for a wide variety of industrial as well as academic applications, e.g.;^[4]

• α-amylase from detergents
• Biotech research & development (e.g., bacterial excretion of amylase)
• Dentistry applications
• Reagent for the clinical diagnosis of pancreatitis
• Specialty chemicals

Forensics

The Phadebas Forensic Press test is used for detecting and identifying hidden saliva stains. Locating saliva stains is a challenging task to perform with light sources as these stains don't fluoresce very well. A study has shown that as many as 40% of saliva stains on garments go undetected when using alternate light sources.^[5] The test is capable of locating saliva deposits on any item or surface. It is said to be selective because alpha-amylase activity in saliva is typically several orders of magnitude higher than in other body fluids.^[6] The methodology has been implemented in forensic labs world wide for many years.

Alimentary

The test is used for determining α-amylase in a wide variety of food applications, for example in Food and Beverages:

• Egg powder
• Wheat
• Milk
• Honey

According to the EU Honey Directive,^[7] diastase activity is a composition criterion that must be determined for honeys intended for human consumption. The official analysis methods for the determination of diastase activity in honey are the [Schade assay] and Phadebas assays, recommended by the International Honey Commission.^[8] As this method is based on fixed equations instead of a standard curve the new Phadebas honey diastase test was developed, to ensure stable results independent of batch.^[9]

References