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Automatic Identification

Performance and productivity expectations for the modern laboratory have never been higher. Test results must be accurate, timely, and provided in the most cost-effective way possible. Fortunately for lab managers, automation technology has advanced.

by Bruce Wray

Today's Automated Lab has a Broad Range of Sophisticated Identification Tools to Choose From

Performance and productivity expectations for the modern laboratory have never been higher. Test results must be accurate, timely, and provided in the most cost-effective way possible. Fortunately for lab managers, automation technology has advanced to meet these heightened expectations. It is no longer a hassle to implement bar code and related automation technologies in the lab.

Several key areas have exploded with innovation over the last several years that, taken together, represent the potential for marked improvement in data accuracy, reliability, and availability throughout the lab’s operations. The areas with the most expanded capabilities are labels, bar code symbologies, printers, print-and-apply systems, sample management software, service bureaus, and RFID. Let’s take a closer look at each one.


It is nearly impossible today to define an end-use environment in which a custom-engineered label won’t work. Label stocks and adhesives today can:

  • Withstand extremely high and low temperatures
  • Resist the harshest of chemicals and stains
  • Remain affixed to a broad range of surfaces, such as microwell plates, tubes and microtubes, slides, vials, and ceramic containers

One innovation that has solved many difficult labeling situations is the “wraparound” label. Especially useful for samples stored in liquid nitrogen, these labels are designed to completely wrap around a tube and stick to themselves; the technical term is “self-laminate.” They are capable of withstanding an autoclave and direct or vapor phase liquid nitrogen exposure. Because of the unique match between the label stock and ribbon, these labels resist solvents such as DMSO, methanol, and isopropyl alcohol, and they can be printed by a thermal transfer printer.

Regardless of label environment, lab managers must still decide whether they will use preprinted or print-on-demand labels. Each has its own advantages and limitations.

Preprinted. In many cases a unique identifier, sometimes referred to as “license plate” identification, makes the most sense. License plate identification, as the name implies, is simply a unique number assigned to a sample. While the number itself contains no significant information (a common trait of preprinted labels), sample origin, tests to be performed, and other sample-specific information are contained in the database and can be accessed upon scanning the unique bar-coded number. This typically has the advantage of shorter bar-coded messages, but it does require database access in order for the user to know how to correctly handle and process the sample.

Print-on-demand solutions are best when significant numbering is required; that is, when the number itself means something. For example, the first two characters indicate the client that owns the sample, the next three characters are the assays to be run, and the final four characters are a simple sequential number for unique ID of that particular sample. When the data that needs to be encoded is not available until a label is required, printon- demand solutions are the obvious choice.

Two-dimensional symbologies

For some labs, there’s no such thing as having too much information encoded on a labeled sample. Their needs extend well beyond a simple linear bar code symbol, and once again technology has more than kept up with this requirement. Now 2-D symbologies, such as DataMatrix, are widely supported; camera-based readers are readily available that no longer command a premium price.

Some applications use a 2-D symbol on the bottom of the tube, which is then read by a fixed-position scanner mounted underneath the workflow. Some labs have taken this to the next level; they scan the 2-D symbol and instantly generate an additional label—either linear, 2-D, or text-only—for use on aliquots or for other processing.

Bar code printers

The days of limited choices in bar code printers are over. Thermal transfer printers are now available in a wide variety of prices and with functionality to match. While familiar brand names may appear to be the de facto standard, sophisticated lab managers are looking beyond those to other suppliers making waves in the market with more features at very competitive prices.

For example, small, low-cost printers are now available for use when lab space is at a premium and budgets are tight. Other firms are offering “standard” printers that are anything but standard when it comes to the features included at no extra cost. Perhaps one of the most useful features is an expanded choice of interfaces, including Ethernet, USB, RS-232, and wireless connectivity.

Print-and-apply systems

Labs with medium- to high-throughput requirements may have installed bar code-based systems years ago. And now, as they look to enhance those systems, can take advantage of “modular” thermal transfer printers that can morph into sophisticated print-and-apply systems. In some cases, a bolt-on assembly can make a thermal transfer printer into a print-and-apply workhorse. And, if the lab’s needs extend beyond those capabilities, specialized systems have been developed for item labeling with placement accuracy tolerances unimaginable even five years ago.

Many labs simultaneously process several types of sample containers that require labeling. There are now print-and-apply systems that can efficiently handle multiple labels for multiple surfaces. Taking up very little space in a crowded lab, these systems can print and apply any customized label from 4x4 mm to 100x100 mm. The device can print (accurately) and place (precisely) up to twelve distinct labels at once on any surface, whether it’s flat or curved.

What’s more, it’s now easier than ever to connect these devices to laboratory information systems, as firms specializing in lab automation have developed software interface expertise for seamless integration.

Sample management software

Whether the products are stand-alone or fully integrated, advances in sample management software packages have been significant. Off-the-shelf products are now available that allow up to 2,000 user-defined fields and can accommodate up to 100 million unique samples, aliquots, or transactions. Client/server versions are available using TCP/IP protocol and a fully automated backup system. These packages handle everything from assigning samples to existing storage facility locations to keeping track of shipping destinations for those samples—and pretty much everything in between.

Service bureaus

The ultimate solution for unique identification of samples in a lab may be to outsource the activity entirely. A few firms offer a hands-off approach for the lab and will deliver ready-to-use prelabeled labware right to a lab’s door. Whether it is slides, microwell plates, tubes, or other containers, labware can be provided to the lab with labels attached either by pressure-sensitive adhesive or through a ceramic symbol that is permanently fired onto the surface. The result? Every prelabeled item is scannable and sequential; no duplicates or unreadable bar codes are provided.

Computype’s Label Ease prelabeled labware service allows companies to rely on labeling experts to provide accurate sample identification.

Tare-weighing services can be added to prelabeling to further enhance lab efficiencies. Because of the critical nature of tare weighing, it is performed in a dedicated, controlled environment. Typical specifications offer weights to 0.1 mg and an accuracy of ±0.2 mg. Tare weighing is available with full traceability, is performed to comply with international standards, and comes with a spreadsheet data summary.

RFID (Radio Frequency Identification)

While it has yet to prove itself as a viable alternative to bar code automation in most labs, RFID holds much promise. It has two technical advantages over bar code technology that may offer benefits in some lab environments: RFID-labeled samples can be read without a line of sight, and the data encoded on the sample container can be changed from a distance. Let’s look at each one of these features.

The operator does not need to see the item(s) being “read” in order to successfully collect the data. Envision a carton of uniquely identified sample containers, each with a “smart label” attached. With the right match between the RFID chips and the hardware, the carton could be sent through a tunnel reader, which could instantly read each and every sample container without opening the carton. Linked to a database containing the identification of every sample expected in the carton, the reader could also indicate whether or not there were missing samples.

The other feature that separates RFID from bar code technology is the ability to change the data encoded without replacing a label. With read-write chips, the data stored can be modified and updated as needed when, for example, specific tests are completed and other procedures added. So although any text on the label wouldn’t reflect the updated information, the chip itself would provide its current status in real time.

The primary limitation to RFID technology is cost. Read-write chips with sufficient data capacity to handle the needs of a laboratory are still expensive, and the hardware to read them is costly as well. In addition, firmware needs to be purchased or developed that provides reliable data handling. While this shouldn’t discourage today’s lab managers from investigating RFID’s potential, it should be a reminder of the importance of comparing costs to expected benefits.

From this review of the status of automation in labs, it’s clear that lab managers have a broad range of identification tools available to them. Choices can be overwhelming, which means that partnerships with trusted and experienced vendors are more important than ever. In order to leverage all the potential benefits of automatic identification and automation in your lab, you need a solution that meets your unique needs. Don’t settle for anything less.