UHF RFID Solution for Laboratory Animals Aims to Boost Productivity, Accuracy

Using Somark Innovation's SensaLab solution, laboratories can read and write data from and to an ultra-small UHF RFID tag embedded in the base of an animal's tail, without requiring technicians to remove the animal from its cage or handle it.
Published: February 27, 2019

Millions of animals, primarily rodents, are used in laboratories each year, and tracking them is predominantly a manual process. While it’s critical to manage the identity and history of each animal, the systems that do so are often cumbersome, with a potential for errors. Unfortunately, the type of RFID technology used to track pets isn’t very practical for small rodents.

Somark Innovations has developed a potential solution known as SensaLab, which is being trialed by laboratories, pharmaceutical companies and universities throughout North America and Europe. The system consists of an ultra-small UHF RFID tag that the firm developed in-house, known as the RFAi.D Tag, that can be implanted in an animal and then be read from a distance of about 5 centimeters (2 inches), thereby reducing the discomfort caused by a large tag, or the need to handle an animal to get the tag close enough to a reader for it to be interrogated.

Jay Campbell

The legacy method for tracking animals consists of a variety of manual processes, says Jay Campbell, Somark’s chief commercial officer. That includes putting visible notches in an animal’s ear or applying a small metal tag to the ear with engraved numbers. In some cases, technicians also apply a physical tattoo on the animal’s tail, or a shaved spot on its hind flank.

Tattooing has become somewhat simpler than it traditionally had been, Campbell notes, with the advent of the Labstamp device in 2012 that restrains an animal and applies the tattoo automatically. However, the system still requires someone to physically read the tattoo’s number at various times during the animal’s life, and manually enter experiment-based data, which is not only time-consuming, but also introduces the potential for transcribing errors, according to Paul Donohue, Somark’s chief technology officer.

In some cases, LF RFID tags are being implanted in animals, though Sensalab argues they are simply too large for rodents, which comprise the vast majority of laboratory animals (approximately 60 to 70 million rodents are used for this purpose annually). LF tags have a shorter read range and can disrupt MRI scans because of their ferrite cores. Another significant advantage of UHF technology involves readability. LF tags must be read one at a time, whereas UHF technology allows for the scanning of multiple tags on animals simultaneously—an advantage that Somark will use in future developments.

Somark developed an alternative system that could automatically capture an animal’s identity as it undergoes specific processes, such as being weighed or having a tumor measured. This solution not only captures the unique ID number of an animal’s tag, but can also write information to that tag, as well as automatically link the animal’s ID with the information being captured, such as its weight on a scale, or the size of a tumor based on caliper measurements. “There’s been a tremendous need to provide a smaller tag in the base of the tail,” Donohue says, “so you know where it is, for better reading.”

Typically, rodents need to be identified when they are still pups. At about the age of 14 days, very small rodents would each need to have a unique ID tag attached or inserted. The tag measures just 0.5 millimeters (0.02 inch) in width, allowing it to be placed at the base of the tail rather than in the body. “The more you look at or touch an animal, it can have an impact on the integrity of the trial,” Campbell states.

Paul Donohue

Somark built the UHF RFID tag using the Monza R6P chip from Impinj. The tag contains a dipole folded copper antenna printed onto Kapton, a polyimide film. The tag measures 6 millimeters (0.2 inch) in length and 0.5 millimeter (0.02 inch) in width. The firm also developed an application process that it calls the low-impact delivery system, by which a 21-gauge syringe is inserted into the skin with a tag inside it, and then retracts, leaving the tag under the animal’s skin. This, the company notes, is a less intrusive alternative to the LF method of pushing the tag directly into the tissue using a large needle.

The tags can be read via Somark readers with built-in Impinj reader modules. The readers can be connected to a device, such as a weighing scale, or they can be mounted in or under the surface on which a cage of animals can be placed, or be provided as a handheld reader. They are loaded with Ai.Connect software to capture each rodent’s tag ID and related data.

In addition, the system comes with cloud-based software employing Microsoft’s Azure platform, which stores each animal’s ID and related information. Each time a tag is read, the collected data is forwarded to the software, where it can be updated and analyzed, and the software can be programmed to write data to the tag as well, if needed. While most companies are initially using the software as a cloud-based solution, Somark offers an open application programming interface for customers that want to integrate it with their existing systems.

The new UHF solution is being piloted by 12 customers throughout North America and Europe, and is expected to be offered commercially in April of this year. The system has been undergoing research and development for three years, Donohue reports, and the initial proof-of-concept testing has already been completed.

In the long term, Campbell says, the system can capture more real-time data than researchers have been able to collect manually. For instance, if an RFID reader and antenna array are mounted under a rodent cage, they could capture each animal’s movements, location and activities for the entire time it remains inside the cage. That means scientists could track such details as which rodent is feeding more or less frequently, what they are feeding on, where they sleep and with what other animals, as well as their fighting patterns and other activities.

The system is designed to be affordable not only to pharmaceutical companies, but also to research laboratories and universities. The tags are low in cost, and users can pay with the SaaS model. Early orders for the solution are already coming in, Campbell notes. Most companies initially want to use the technology integrated with their weight scales, he adds, though any digital device used on an animal could be integrated with the RFID system. Somark also intends to develop larger tags with longer read ranges for other lab animals, at the request of customers.