A Performance Verification System Assures Accurate and Precise Data from Refurbished Automated Liquid Handlers

Low-volume liquid handling is a core component of almost every modern laboratory. With continued advances in the automation of liquid handling, laboratories are realizing new gains in throughput and overall efficiency. With these industry advances comes a growing focus on quality and the need to ensure that all equipment is performing to specifications all of the time.

However, as budgets for laboratory equipment get tighter, many laboratory managers are purchasing used equipment in an effort to stretch their limited funds. Yet when purchasing used or refurbished equipment from auction sites, equipment brokers and third-party vendors, laboratories aren’t always provided with product certification to guarantee that their equipment will operate according to the manufacturer’s specifications upon arrival.

Biodirect Inc. is a company aiming to raise the bar of assurance for lab managers purchasing pre-owned equipment. Located in Taunton, Mass., the company sells an array of pre-owned laboratory equipment, including dispensers, thermal cyclers, incubators, centrifuges and microplate detection systems. All equipment, including automated liquid handlers, is guaranteed to meet the original manufacturer’s specifications.

Because of customer need for automated liquid handlers with proven accuracy and precision, Biodirect has recently upgraded its liquid handling quality control program. Now, as part of the quality system, the performance of each automated liquid handler is validated for precision and accuracy using the Multichannel Verification System (MVS®) from ARTEL (Westbrook, Maine), and subsequently sold as “ARTEL Certified.”

Importance of quality

For Biodirect’s customers, precise and accurate automated liquid handling is essential. Many laboratories today work with extremely rare and expensive reagents that can cost thousands of dollars per liter. Any dispensing inaccuracy can lead to unnecessary waste, increased costs and loss of precious reagent. Because automated liquid handlers process very minute volumes, performance verification is critical. Inaccuracies as slight as a fraction of one microliter have the potential to drastically alter results.

Biodirect’s equipment validation processes contribute to the avoidance of errors by refurbishing, reconditioning and customizing automated liquid handlers using the original manufacturer’s specifications as a baseline for quality. This procedure ensures that customers receive the same or better results from their refurbished equipment as they would from a brand-new automated liquid handler purchased directly from a manufacturer.

“We put automated liquid handlers through rigorous testing to ensure that every aspect of the machine is working to manufacturer’s specifications, alleviating our customers of this burden,” said Rich Tula, CEO, Biodirect Inc.

Certifiably accurate

When an automated liquid handler is obtained by Biodirect, it undergoes an extensive maintenance inspection for the identification of deficiencies and any worn or missing parts. At the end of the inspection, the ARTEL MVS is used to thoroughly assess the instrument’s accuracy and precision on a channel-bychannel basis in one rapid experiment.

The ARTEL MVS is based on proprietary ratiometric photometry, which is a dual-dye, dual-wavelength photometric method for accurate and precise measurement of small target volumes. Described in the ISO 8655 part 7 guideline of the International Organization for Standardization, this technology uses two dyes with distinct absorbance maxima at 520 nm (red dye) and 730 nm (blue dye). The MVS is used to quantify volume dispensed from each channel or tip of an automated liquid handler into a microplate by measuring the absorbance of these dyes, calculating volumes and flagging any deliveries outside of preset tolerances.

When purchasing a liquid handler from Biodirect, customers receive a checklist detailing all service checks and refurbishing tests that have been conducted, thereby verifying the performance of the liquid handler in each test. The company also provides automatically generated, detailed reports from the MVS showing the volume transfer performance of the instrument during the calibration event. These reports provide summary statistics by channel, by row and by column. The MVS also provides results that are traceable to international standards, allowing for comparability of all liquid handling devices regardless of model, location or number of dispensing channels.

For example, a laboratory recently purchased a refurbished automated liquid handler from Biodirect to complement its existing automated liquid handler. Biodirect completed a comprehensive preventive maintenance inspection and installed a low-volume option on the refurbished automated liquid handler so that it could perform as well as the existing automated liquid handler. However, laboratory staff experienced different results with the two systems and questioned the validity of the refurbished system from Biodirect. The NIST-traceable results and documentation provided by the ARTEL MVS provided indisputable proof that the refurbished system performed well within laboratory specifications with an accuracy tolerance of 5 percent for a target volume of 50 microliters. As a result, the laboratory requested that Biodirect use the MVS to test the accuracy and precision of the original automated liquid hander.

”We strive to go above and beyond customer expectations. We do this by not only repairing equipment to manufacturer specifications, but by also verifying dispensing accuracy and precision with the MVS,” said Tula.

Improved methodology

Before incorporating the MVS into its quality assurance processes, Biodirect relied on gravimetric technology to measure the performance of its refurbished liquid handling devices, and this method was time-consuming and tedious. Verification of one automated liquid handler using gravimetry required approximately four hours of labor, as compared to the 30 minutes required with the MVS. Additionally, the results provided by the gravimetric method were affected by environmental conditions (especially humidity). Another drawback was that gravimetry only provided an average assessment of volume dispensed from the liquid handler, while the MVS provides information on the exact volume dispensed from each individual channel.

In addition to gravimetry, Biodirect previously used a microplate reader and commercial dyes to test the precision performance of its refurbished automated liquid handlers. These dyes required a dilution step, causing the method to be lengthy and untraceable.

“My staff is always excited to get tools that help them do their jobs better and faster. With the MVS, they’re now able to get their jobs done quicker with a higher quality end product,” said Tula.

For more information about Biodirect and its certified pre-owned laboratory product offerings, visit www.biodirectUSA.com. For more information about the ARTEL MVS and other liquid handling quality assurance products and services, visit www.artel-usa.com.