Precision-Engineered Lateral Flow Cassettes for Rapid Diagnostics
- TN Plastics
- Jan 28
- 4 min read
Lateral flow tests remain one of the most widely used formats for rapid diagnostics and point-of-care testing—and the plastic cassette around the strip is far more than simple packaging. It is a critical component that protects the assay, controls fluid flow, and shapes the end-user experience.
At TN Plastics, we design and manufacture precision-molded lateral flow cassettes that meet the performance, quality, and scalability demands of modern IVD and point-of-care platforms.
What Is a Lateral Flow Cassette?
A lateral flow cassette is the plastic housing that holds the nitrocellulose strip and its associated pads in a lateral flow assay. It protects the sensitive test components, guides sample application, and presents clear test and control lines for result interpretation.
Inside a typical cassette you will find:
Nitrocellulose membrane (test strip)
Sample and conjugate pads
Absorbent pad
Sample wells and channels that direct fluid
Test and control line viewing windows
When these elements are aligned and retained consistently, the assay delivers reliable capillary flow, clear visual lines, and reproducible performance across high volumes.
Why Cassette Design and Molding Quality Matter
Lateral flow assays are only as consistent as the hardware that surrounds them. Small variations in geometry, fit, or surface quality can translate into big differences in performance.
Key aspects where cassette quality has a direct impact:
Assay alignment and retentionTight dimensional control keeps membranes and pads in the correct position, ensuring consistent fluid travel across test and control zones.
Fluid flow and wickingPrecisely molded sample wells, channels, and venting features help achieve reliable capillary action and minimize edge effects or incomplete flow.
Signal visibilityClear, well-defined windows and uniform background surfaces improve contrast and make faint test lines easier to read.
Protection and stabilityRobust housings protect strips from physical damage, dust, and ambient contamination—from packaging through transport and end use.
Precision Injection Molding for High-Volume Diagnostics
Our lateral flow cassettes are manufactured using high-precision injection molding, with a focus on tight tolerances and repeatability across millions of parts.
Design and manufacturing highlights include:
Controlled dimensions for accurate placement and retention of nitrocellulose membranes, sample pads, conjugate pads, and absorbent pads
Tightly controlled sample wells, test/control windows, and membrane channels to support repeatable capillary flow
Compatibility with automated pick-and-place, lamination, and inline assembly systems
Options for runners, gates, and parting lines tuned to protect critical sealing and functional areas
This combination supports cost-effective, high-volume production while protecting the integrity of the assay.
Built for Automated Assembly and Scale-Up
Most successful lateral flow platforms live or die on their ability to scale. Cassettes must work seamlessly with automated equipment from development builds through full commercial ramp.
We design cassettes to:
Integrate into automated membrane lamination and assembly lines
Support efficient assay loading, sealing, and packaging
Maintain consistent fit and function as volumes scale from pilot runs to millions of units
This reduces rework at scale-up, shortens validation timelines, and helps OEMs protect cost per test as volumes grow.
Cleanroom Manufacturing and Regulatory Readiness
For regulated IVD and point-of-care products, managing contamination risk and documentation is non-negotiable.
Our lateral flow cassette offerings can include:
Cleanroom molding options to reduce particle and bioburden risk
Manufacturing practices aligned with IVD expectations and quality system requirements
Process controls and inspections to support verification, validation, and ongoing monitoring
This foundation helps OEMs align their cassette hardware strategy with broader regulatory and quality objectives.
Material and Design Options for Performance
The right material and design choices are essential for both assay performance and user acceptance.
Typical engineering considerations:
Medical-grade thermoplasticsSelected for dimensional stability, chemical resistance to reagents and buffers, and durability under storage and use conditions.
Closure and sealing optionsSnap-fit features, ultrasonic welding compatibility, and bonding surfaces are engineered to support robust sealing and long-term integrity.
Ergonomic handlingThoughtful geometry for sample application, cassette handling, and readout orientation improves usability for clinicians and lay users.
Branding and customizationOptions include custom color, logo embossing, labeling areas, window shapes, and overall form factor tailored to your brand and workflow.
From Prototype to High-Volume Manufacturing
Whether you are launching a new lateral flow product or transferring an existing design to a more robust supply chain, our approach is built around consistency and scalability.
We support OEMs with:
Prototype tooling for design validation and initial performance testing
Design-for-manufacturability input to optimize features for molding, assembly, and sealing
Advanced tooling and process control to maintain tight tolerances across cavities and lots
In-process inspection and data-driven quality monitoring to ensure repeatable performance
The result: lateral flow cassettes that are ready for today’s rapid diagnostic demands and tomorrow’s volume growth.
Key Benefits of Our Lateral Flow Cassette
Precision-molded housing for consistent assay alignment
Supports high-volume, automated assembly
Cleanroom manufacturing options available
Medical-grade material selections for durability and compatibility
Customizable design, branding, and form factor
Ideal for rapid diagnostics and point-of-care testing environments
Meet TN Plastics at MD&M West
If you are attending MD&M West, TN Plastics will be on-site to discuss lateral flow cassette design, tooling, and scale-up in person. This event is an ideal setting to explore how cassette geometry, material selection, and assembly strategy can de-risk your next rapid diagnostic program and shorten time to market.
Our team will be available to review current or planned lateral flow formats, talk through cleanroom molding and validation needs, and identify practical paths from prototype builds to stable, high-volume supply. Whether you are launching a new assay, expanding capacity, or considering a second source, we welcome the opportunity to connect at the show.
Ready to Advance Your Lateral Flow Platform?
The lateral flow cassette is a small component with outsized impact on assay performance, manufacturability, and user confidence. Choosing a partner with deep experience in precision molding, cleanroom manufacturing, and scalable assembly can help ensure your rapid tests are reliable at the bench, in the clinic, and at commercial scale.
If you are developing or scaling lateral flow assays and want to strengthen your hardware foundation, we invite you to start a conversation with TN Plastics. Contact our team today to discuss your cassette design, tooling, and manufacturing needs—or schedule time to meet with us at MD&M West—and explore how we can support your next generation of rapid diagnostic and point-of-care products.
