In lateral flow testing, particularly in quantitative and semi-quantitative assays, the uniformity and reproducibility of reagent lines are important to the consistency of test signals. The coefficient of variation (CV) is one measure used to assess process performance. Variations in reagent volume, line width and line position place demands on equipment stability, dispensing accuracy and repeatability. The dispensing process forms the reaction lines and connects development formulations with manufacturing.
ATLAS LINK TECHNOLOGY selects reagent dispensing equipment from multiple manufacturers according to process requirements. Its equipment includes several BioDot systems used in product development and manufacturing process work.
To support consistent reagent deposition, ATLAS LINK matches equipment selection to reagent formulations, dispensing methods and production scale. Defining deposition volumes, line positions and operating conditions enables researchers to compare and reproduce experimental conditions while retaining traceable process information for manufacturing execution and investigations of batch variation.
More Than a Decade of Equipment Application and Process Experience
ATLAS LINK began introducing BioDot equipment more than a decade ago and has continued to apply it in reagent deposition processes for product development and manufacturing. Since 1994, BioDot has provided dispensing, cutting and lamination technologies to the lateral flow industry, with applications in infectious disease testing, fertility testing, drugs-of-abuse screening and other rapid tests.[1]
The technologies include FrontLine for contact striping on membranes, BioJet for non-contact reagent dispensing and AirJet for conjugate application and material treatment. Each method serves a different process step, allowing the equipment configuration to be matched to reagent properties, material characteristics and product design.[2]
For ATLAS LINK, this equipment portfolio, developed around lateral flow processes, provides defined technological options for product development and manufacturing. Equipment applications need to be studied using the actual formulations and materials so that the dispensing method is appropriate for the product requirements.
From Nanoliter Dispensing to Control of Reagent Volume per Unit Length
BioJet combines a drop-on-demand valve with a high-resolution syringe pump. Its current technical information lists a typical single-drop volume range of 2.0 nL to 2.0 μL and a dispensed volume per unit length of 0.5 to 3.0 μL/cm. Non-contact dispensing applies reagent without the dispensing tip sliding across the membrane surface.[3]
FrontLine uses a flexible microtube in contact with the membrane surface and synchronizes fluid flow with platform motion to create a reagent line metered by unit length. Its published typical line width is 0.25 to 2.5 mm, and the dispensed volume per unit length can be programmed.[4] The published range is a manufacturer specification; the shape of a dried line still needs to be evaluated using the membrane, reagent, volume and operating conditions of the specific process.
The value of these technologies in development lies in converting the amount and placement of reagent into parameters that can be clearly recorded and compared.
In developing reagent deposition processes, ATLAS LINK focuses on the relationships among reagent concentration, dispensed volume per unit length, line position, membrane material and drying conditions. Controlled dispensing conditions allow researchers to compare the performance of different formulations and raw material combinations, providing evidence for selecting suitable processes.
The amount of protein applied to the membrane must also be evaluated in relation to its actual immobilization and functional performance. Quantitative dispensing provides controlled experimental conditions, while product testing establishes whether those conditions are suitable.
Independent Channels and Programmable Settings Support Multi-Line Development
When developing multiplex respiratory antigen tests and multi-drug screening tests, different analytes may be accommodated by multiple test lines or by a combination of separate test strips. ATLAS LINK studies the reagent formulation, dispensing volume and position of each test and control line according to the product configuration. Designs with multiple lines on the same membrane also require evaluation of line spacing and compatibility among the lines.
For example, BioDot’s official information states that the ZX1010 can be configured with 1 to 8 dispensing channels, with independent volume control for each channel. It supports simultaneous quantitative dispensing, programmable line lengths and volumes, and storage of multiple programs.[5]
The XYZ3060 and XYZ3210 additionally provide programmable X, Y and Z axes, allowing dispensing positions and motion parameters to be included in program settings.[6][7]
These functions support development through both liquid metering and the organization and reproduction of experimental conditions.
ATLAS LINK places importance on linking equipment settings to experiment identifiers, reagent lots, membrane lots and test results. When comparing signal, background and performance with low-concentration samples, researchers can refer back to the specific formulations and deposition conditions to assess the changes associated with parameter adjustments.
Using Equipment Specifications to Support Process Evaluation
The BioDot XYZ series specification sheet lists the accuracy of the relevant dispensing technologies as ±5% of the target, subject to platform speed, material and reagent. The same document lists a typical axial system precision of less than 10 μm for the XYZ models.[8]
These specifications describe the capabilities of the liquid dispensing and motion systems, respectively, and provide references for equipment verification and process studies. CV describes the relative dispersion of repeated measurements under defined conditions; the measured quantity must be specified, whether dispensing volume, line width or test signal. Dispensing accuracy, positioning precision and CV should be evaluated separately.
In ATLAS LINK’s process evaluations, equipment settings need to be assessed using the actual deposition solutions and membrane materials. Dispensing volumes, line characteristics and subsequent functional test results should be considered together to establish suitable operating conditions and acceptance requirements.
This evaluation translates equipment specifications into process evidence applicable to a specific product and supports reproducible manufacturing.
Maintaining Process Continuity from Development to Manufacturing
When a development process moves into manufacturing, changes in equipment and processing scale may introduce new sources of variation. Continuity in the core dispensing technology can help reduce the complexity of this transfer.
For ATLAS LINK, transfer from development to manufacturing needs to include material requirements, formulations, equipment parameters, drying conditions and evaluation methods. Comparing corresponding conditions and product results establishes the suitability of the process in the manufacturing environment, allowing development findings to continue guiding production.
Focus on Reagent Supply, Materials and In-Process Inspection in Continuous Production
The continuity of reagent supply and the condition of material transport during extended operation also affect reagent deposition.
During continuous reagent deposition, ATLAS LINK focuses its process checks on continuity of reagent supply, material positioning and line condition, taking into account the material format and actual equipment configuration. Roll-based processes also require attention to the relationship among material tension, running speed and dispensing volume, with deposition quality evaluated in conjunction with subsequent drying conditions.
Based on its actual equipment configuration, ATLAS LINK focuses on reagent supply, material positioning, interruptions to operation, cleaning and maintenance, and drying and storage conditions. Linking this information to intermediate product batches and inspection results helps define the affected scope when an anomaly occurs and investigate potential causes involving materials, equipment or operations.
Building a Traceable Manufacturing Process
BioDot’s service information includes installation qualification, operational qualification, accuracy and precision verification, software and firmware version records, and maintenance documentation as elements of its equipment support, providing technical information for equipment lifecycle management.[10]
For ATLAS LINK, the value of precision dispensing equipment is realized through trained operators, equipment maintenance, process evaluation and records management.
From raw material and formulation studies to deposition parameter screening, transfer to manufacturing and routine production, ATLAS LINK will continue to align equipment applications with specific product requirements, providing a reproducible and traceable process foundation for the NOVAtest® brand and OEM and ODM partnerships.
Precision begins with every test line.
Technical Specifications and Application Evidence
The specifications below are published by BioDot for the corresponding technologies or systems. They do not represent the configurations or measured capabilities of all equipment in use at ATLAS LINK.
The dispensing volumes and line widths above are typical application ranges published by the manufacturer. Differences between document versions were also identified: for example, the current BioJet technology page gives a minimum single-drop volume of 2.0 nL, whereas the XYZ-specific specification sheet states 2.6 nL. Specifications used to describe the company’s equipment therefore need to correspond to the model and configuration in use.[3][8]
Reference
[1] BioDot, “Lateral Flow,” application page.
[2] BioDot, Lateral Flow Solutions, brochure BDM-BR-LFSOL-009-01, pp. 6–8.
[3] BioDot, “BioJet™,” technology page.
[4] BioDot, “FrontLine™,” technology page.
[5] BioDot, “ZX1010™ Dispense System,” product page.
[6] BioDot, “XYZ3060™ Dispense System,” product page.
[7] BioDot, “XYZ3210™ Dispense System,” product page.
[8] BioDot, XYZ Batch Dispensing, specification sheet BDM-DS-XYZDS-019-02, p. 2.
[9] BioDot, “RR120™ Web Handling System,” product page.
[10] BioDot, Comprehensive Service Guide, brochure BDM-BR-GSERV-01-03, pp. 9–10.
[11] BioDot, “AirJet™,” technology page.
[12] BioDot, “µAirJet™,” technology page.
[13] BioDot, RR120 Specifications, data sheet BDM-DS-RR120-014-02.