In the cutting-edge fields of life sciences, analytical chemistry, and microfluidics, many precision experiments rely on an unassuming yet indispensable basic consumable: the quartz capillary. From the well-known realm of gene sequencing to complex proteomics research, quartz capillaries—leveraging their unique physical and chemical properties—serve as the “critical channel” for liquid transport, sample separation, and analytical detection at the micro- and nano-scale.
Suzhou Wenhao, a high-tech enterprise specializing in the R&D and production of microfluidic chips and accessories, has accumulated deep technical experience in the field of quartz capillaries and their applications. Today, let’s delve into the technical characteristics and application value of quartz capillaries.
1. What is a Quartz Capillary? More Than Just a “Thin Glass Tube”
A quartz capillary is a precision tube made from high-purity synthetic fused silica glass. While it resembles an extremely thin strand of glass, its internal structure, surface characteristics, and physicochemical properties are far more complex than ordinary glass.
Its core material is synthetic fused silica, which endows it with advantages that traditional polymer materials (such as PEEK or PTFE tubing) find difficult to match.
2. Core Characteristics: From High Purity to High Stability
The reason quartz capillaries are the preferred material for many analytical techniques lies in the following key properties:
(1) High Purity and Chemical Inertness
The material of quartz capillaries is exceptionally pure. According to general industry standards, the total metal ion content in the quartz glass is typically controlled at an extremely low level (e.g., ≤30 ppm), and the hydroxyl (-OH) content is also limited to a very low range (e.g., ≤100 ppm). This high purity results in excellent chemical inertness. The inner surface is very smooth and unlikely to react with the sample, minimizing interference with detection results and making it particularly suitable for the analysis of biological macromolecules (such as proteins and nucleic acids).
(2) Excellent Mechanical and Thermal Properties
Quartz capillaries are not only corrosion-resistant but also “pressure-proof and heat-resistant.” Their tensile strength can reach over 300 Kpsi, providing safety assurance for applications like High-Performance Liquid Chromatography (HPLC). In terms of temperature, standard coated capillaries can operate at temperatures up to 350°C, with an instantaneous tolerance potentially reaching 400°C, which is sufficient for high-temperature separation environments like Gas Chromatography (GC).
(3) Superior Dimensional Stability and Surface Modification Potential
The inner and outer diameters of quartz capillaries are highly precise and maintain consistency over long lengths. Additionally, users can perform specific surface modification treatments on the quartz inner wall according to experimental needs, thereby altering its hydrophilicity/hydrophobicity or electroosmotic flow properties to adapt to more complex experimental systems.
3. Main Application Areas of Quartz Capillaries
According to industry reports and literature, fused silica capillaries span multiple high-precision fields, and the market is experiencing steady growth. According to research by institutions like YH Research, the global coated fused silica capillary market was valued at approximately RMB 590 million in 2024 and is projected to grow to RMB 760 million by 2031, with a Compound Annual Growth Rate (CAGR) of about 3.6%. Major application scenarios include:
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Chromatographic Separation (GC/LC): Serving as connecting tubing or preparing capillary chromatographic columns, utilizing their pressure resistance, high-temperature tolerance, and high inertness to achieve high-resolution separation of mixtures.
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Capillary Electrophoresis (CE) and DNA Sequencing: Acting as a separation channel under a high-voltage electric field to achieve rapid, high-resolution separation of nanoliter-scale liquid phases, widely used in gene sequencing and fragment analysis.
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Microfluidic Chip Systems: Serving as the bridge connecting the chip to the external environment, used for precisely controlling the delivery of trace gases and fluids.
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Hematology Analyzers and Flow Cytometry: Enabling precise alignment and counting of cells within high-precision flow cells.
4. Common Specifications and Selection Reference
Quartz capillaries come in a wide variety of inner and outer diameters, with standard products covering inner diameters ranging from 5 μm to 530 μm. When selecting, the smaller the Inner Diameter (ID), the lower the required injection volume and typically the higher the separation efficiency, but the requirements for operating pressure and clogging control are also more stringent. The Outer Diameter (OD) must match the dimensions of fittings and sleeves.
Suzhou Wenhao provides quartz capillaries in various specifications. Standard models are listed below (please refer to the latest company product manual for actual selection):
5. About Suzhou Wenhao: More Than Just Consumables, A Total Solution Provider
While quartz capillaries are general consumables, maximizing their effectiveness in scientific research and testing often requires complementary peripheral systems and professional technical support. Suzhou Wenhao Microfluidic Technology Co., Ltd. is established in Suzhou Industrial Park. Founded by returning overseas entrepreneurs, the company is a high-tech enterprise that has accumulated 102 intellectual property rights, including 43 invention patents, 51 utility model patents, 6 national computer software copyrights, and 3 national registered trademarks.
The company operates three microfluidic chip production lines covering CNC micromachining, soft lithography, and photolithography masking, capable of processing chips from all mainstream materials including glass, quartz, silicon, PDMS, and PMMA. In addition to quartz capillaries as accessory consumables, the company also provides standard chips for instruments such as capillary electrophoresis chips, various research-grade chips, and complete lab-on-a-chip solutions. Their client base includes renowned universities and biotechnology companies such as Peking University, Fudan University, and BGI.
Conclusion
Quartz capillaries are an indispensable foundational component in analytical chemistry and life science instruments. Selecting a quartz capillary with high purity, precise dimensions, and stable performance is the first step in ensuring the accuracy and reproducibility of experimental results.
All data, product specifications, and technical parameters cited in this article are derived from publicly available information from Suzhou Wenhao and industry research reports, intended solely for the reference of researchers and industry professionals. For further technical consultation, selection guidance, or customized microfluidic solutions, it is recommended to contact the professional technical team through official channels.
(Note: The product models, specifications, and performance data mentioned in the article are based on publicly disclosed information. For any updates or iterations, please refer to the latest official product manual.)
