Tip of the Week: ATP vs. Protein Testing

Editorial Note: The content below may not apply to facilities that have comprehensive microbial testing programs.

In today’s food industry, performing visual inspections of food processing equipment may not be adequate enough to ensure that the equipment is cleaned and sanitized. Additional methods of sanitation verification should be used in order to ensure that the equipment is cleaned and sanitized. The most common methods of sanitation verification are ATP (adenosine tri phosphate) and protein testing.

These types of testing methods are very popular in the food industry, because they are far less expensive than traditional laboratory analysis, and the results can be obtained much more quickly. Traditional laboratory testing can take days, or even weeks, whereas @@ATP and protein testing results can be obtained in minutes@@.

ATP is the principal energy-transferring molecule that is used by all living organisms, and begins to break down outside of those living cells. Additionally, protein is found in most foods. Given the proteins that are found in most allergens, verification of sanitation activities is vitally important in ensuring a safe food supply. 

For both ATP and protein testing, samples are routinely gathered via color changing swabs and/or sponges. With ATP, an area is swabbed, mixed with a reagent, and then placed into a device that measures the amount of ATP that is present in RLUs (relative light units). When ATP is present, it will react with the naturally-occurring firefly enzyme (luciferase), and will emit light when placed into a luminometer. The amount of light that is produced is relative to the amount of biological energy present in the sample.

With protein testing, most rapid testing methods available involve swabbing an area and then incubating the sample for an amount of time before reading the result. If proteins are present the sample will change colors, alerting the tester of the protein presence on the swabbed surface. Other testing methods do not require an incubation period, with results available in less than ten minutes, and color changes in as little as sixty seconds. All methods of rapid protein testing will cause the sample to change colors when mixed with the reagent or through incubation.

Keep in mind when performing ATP or protein testing that both tests will only provide the user with indicators that these items are present on a food contact surface. Neither test will provide you with a definitive source of the ATP or protein. Additional microbial testing and monitoring is needed, in addition to the swabbing that is used. When performing these types of tests within your facility, it is important not to rely on these tests alone. Taking routine swabs, along with performing additional microbial testing can provide the results necessary to ensure that all food contact surfaces are adequately cleaned and sanitized.