Plant tissues and animal organs are the most important sources of enzymes in the growing field of enzyme biotechnology. About 70% of the enzymes are extracted from plant tissues or exudates and animal organs. Animal derived enzymes represent about 10% of the total enzyme market. Alcohol dehydrogenases (ADH) are a group of dehydrogenase enzymes that occur in many organisms and facilitate the interconversion between alcohols and aldehydes or ketones . It is believed that chicken liver is a good source of ADHs. Therefore, in the present study, chicken liver was selected as an affordable, accessible, animal organ, which is rich in a vast variety of enzymes, including ADH, and the goal of this study was extraction and enrichment of ADH from chicken liver. Recovery and purification of biological products is a complex process that usually its production cost is relatively higher than the normal commodities and goods. In recent years, the production of new proteins in the biotechnology industry, using simple and inexpensive separation methods has attracted much attention. Conventional protein purification processes are multistep processes that involve a significant loss of enzyme activity. One of the promising methods for enzyme separation and enrichment is foam fractionation. It is believed that separation of proteins using foam would minimize the separation steps, and would maintain satisfactory purification efficiency. In this method, generated bubbles in the solutions that contain surfactants and enzymes create a gas - liquid interface that adsorb the active substances. Micron size bubbles called “aphrons” have shown a good potential for separation of enzymes with high efficiency. This is because of the fact that aphrons would enhance the transfer of the enzyme to the aphron phase by increasing the gas-liquid interface through reduced bubble size and as a result increased specific mass transfer area. So, in this research project micro bubbles were used for the extraction and enrichment of ADH enzyme. In order to produce bubbles, ultrasonic homogenizer at various speeds and in different time spans was used to agitate and blend the surfactant-containing aqueous solutions. Then, a certain volume of bubbles was mixed with solution containing the enzyme mixture and enough contact time was spared for enzyme isolation. To investigate the effects of mixing and surfactant on possible enzyme denaturation of the isolated enzymes, electrophoresis was used. Enzyme concentration was determined via light absorption of UV and Beer-Lambert correlation was used to calculate the enzyme concentration. The results showed that the type and concentration of the surfactants, pH, and the presence of salts had profound effects on enrichment. At first, experiments were performed using anionic and cationic surfactants and finally AOT was selected as the best surfactant. The salts used for extraction were KCl and NaCl. Results showed that in the presence of KCl and at a concentration of 6 mM AOT and at a pH value of 6, smaller bubbles were generated, and the highest enrichment yield was obtained (238.9 %). Measured bubble sizes using light microscope were about 10-100 micrometer. Experimental observations indicated that generation of nano-sized bubbles in presence of KCl would be plausible; however, because of the unavailability of suitable measuring devices, identification of nanobubbles was not explored. In addition, electrophoresis results confirmed the enrichment, and indicated that the isolated Alcohol Dehydrogenases were not denatured.