Tissue Digestion - The Tissue Digestion Process

> Chemistry of the WR2 Process
> Composition of Animal Tissues
> Effects of Alkaline Hydrolysis
> Results of the WR2 Process
> Applications of the WR2 Process
> Aldehyde-Containing Fixatives and Embalming Fluids
> Infectious Waste
> Biological Warfare Agents
> Chemotherapeutic Agents
> Control and Safety Systems

Chemistry of the Biosafe/WR2 Process

Hydrolysis is a process whereby chemical bonds are broken by the insertion of water between the atoms in the bond. Hydrolysis can be catalyzed by enzymes, metal salts, acids, or bases. Bases are typically water solutions of alkali metal hydroxides such as sodium hydroxide (NaOH) or potassium hydroxide (KOH). Heating the reactants dramatically accelerates the hydrolysis reaction. Just as proteins, nucleic acids, polymeric carbohydrates, and lipids were made by organisms via condensation of building blocks, so can they be depolymerized i.e., unmade, by hydrolysis? The BioSAFE/WR2 Process thus destroys all of these classes of compounds by alkaline hydrolysis, reducing them to their building blocks and, in some cases, degrading them even further into smaller molecules. The BioSAFE/WR2 Process was developed as an alkaline hydrolysis process for the rapid destruction of tissue components without deleterious effects on either the environment or the construction materials - stainless steel and Teflon -of the wetted parts of the Digestor.

Amino acids, the building blocks of all proteins, can be represented as shown below:


Amino acids are linked to each other in a peptide (amide) bond in which the carboxyl group of one amino acid is condensed to the amino group of another amino acid with elimination of water.  The resulting polymer is called a polypeptide or protein.  All polypeptides consist primarily of the elements carbon, hydrogen, nitrogen, and oxygen, along with smaller amounts of other elements, mainly sulfur and phosphorous.  Hydrolysis reverses the condensation of amino acids into proteins by the acid- or alkali- catalyzed breaking of the peptide bonds and the addition of water at the break.  In the BioSAFE/WR2 Process, alkali, in the form of either sodium or potassium hydroxide solution, is used at elevated temperatures for rapid dissolution and then hydrolysis of the proteins into small peptides and amino acids (in the form of their sodium or potassium salts).  Potassium hydroxide or mixtures of potassium hydroxide and sodium hydroxide are the preferred alkali solutions because of the instability of concentrated (50%) NaOH solutions at temperatures below 20°C.  All proteins, regardless of their origin, are destroyed during the alkaline hydrolysis.