Global demand for animal protein continues to increase due to population growth and lifestyle changes in developing economies. To improve the efficiency of meat production, enzymes, such as cellulose, β-glucanases, xylanases, proteases, lipases and galactosidases, are commonly added to animal feed to aid digestibility and enhance nutritional value. By making feed more nutritious, enzyme supplementation helps improve animal health, increase growth performance and reduce the environmental impact of livestock farming by minimizing waste nutrient content.
As bioactive molecules, animal feed enzymes are sensitive to the conditions in which they operate, and their activity may decrease in the presence of other ingredients or during storage. Determining enzyme activity is, therefore, essential for protecting the quality and safety of feed formulations, and helps ensure the authenticity and traceability of products. However, current manual laboratory methods for assessing enzyme activity are associated with several limitations that make them slow and inefficient in practice.
Here, we consider the challenges encountered with traditional enzyme assay methods, and how modern automated analyzer technologies can overcome them.
Traditional enzyme assay methods suffer from multiple challenges
The traditional approach for determining enzymatic activity involves the use of manual enzyme assay methods. These experiments typically follow the course of the enzyme-catalyzed reaction by monitoring changes in the concentration of substrates or products.
Many enzyme assays are based on spectroscopic techniques, which measure changes in the intensity of light absorbed or scattered by the solution as the reaction progresses. However, the accuracy of these experiments is sensitive to factors, such as temperature, pH, buffer type and ionic strength, which must all be carefully controlled. For some assays, reactions cannot be studied in real time, and require samples to be taken at regular intervals, quenched to prevent further reaction and analyzed using high-performance liquid chromatography (HPLC). A single result can take around 30 minutes to obtain using this approach. Given these challenges, spectrophotometric assays are often lengthy and labor-intensive to set up and run, limiting their use to applications involving just a few samples.
Assays based on photometry, fluorometry, 96-, 384- or 1,536-well format microplates are widely used for high-throughput enzymatic analysis applications. However, microplate-based methods present several additional challenges, including the need for pathlength correction, as well as the ”edge effect” phenomenon, which can result in wells located around the outer edge of microplates evaporating more quickly than those in the center, affecting reliability. As a result, method development can be tedious and time-consuming, requiring careful control of manual steps to ensure assay accuracy and transferability.
Enzyme assay automation: Improving reliability and simplifying method development
Automated technologies are helping to streamline method development and deliver more rigorous enzyme assay results in animal feed analysis.
The Thermo Scientific™ Gallery™ Enzyme Master and Thermo Scientific Gallery Plus Enzyme Master enzyme an... are the first fully automated discrete analyzers designed specifically for enzyme assays. By automating the key steps involved in enzyme analysis, including liquid handling, incubation time and incubation temperature, Gallery Enzyme Master enzyme analyzers provide precision control over the variables affecting assay results, making method development faster and more convenient. Once samples and reagents are loaded into the analyzers and the method is selected, laboratory professionals can walk away and focus on other tasks, increasing day-to-day productivity.
The enzyme analyzers offer superior temperature control by automatically grouping samples requiring the same incubation temperature and heating at the lowest temperatures first. This innovative approach reduces temperature-based inconsistencies and eliminates the ”edge effect,” improving accuracy and assuring confidence in results. Furthermore, by supporting real-time kinetic measurement, the enzyme analyzers can deliver up to 350 results per hour, significantly boosting throughput to shorten method development.
Both enzyme analyzers offer a wide range of incubation temperatures from 25° C to 60° C and wavelength coverage from 340 nm to 880 nm, enabling efficient handling of many different enzymes and measuring conditions in a single instrument. This versatility provides comprehensive support for animal feed assays and analysis of the many different types of enzymes present in feed products.
Developing and executing reliable methods for enzyme analysis used to be time-consuming and complex, with traditional assays producing variable results due to the difficulties associated with controlling experimental conditions. Fully-automated analyzers provide an efficient solution to the challenge of enzyme analysis, generating robust results at the push of a button.