What are NanoFil™ Needles?

NanoFil™ needles are precision-engineered stainless-steel injection tips designed exclusively for use with WPI's NanoFil™ gas-tight syringe system. Available from 26G down to 36G — the smallest commercially available gauge — they enable accurate sub-microliter delivery in stereotaxic, viral-vector, and ophthalmic research workflows.

Each needle is hand-finished, individually inspected, and mounted on a 26G base to ensure mechanical rigidity and a universal fit across every NanoFil syringe in a lab's inventory. Two tip geometries are available: blunt for soft-tissue injections and uniform sample distribution, and a unique 25° tri-surface beveled tip optimised for penetration through tougher tissue with minimal mechanical damage.

Key Features

• Smallest gauge on the market: Down to 36G (110 µm OD, 35 µm ID), enabling sub-nanoliter injection accuracy by minimising diffusion at the tip.
• Patented 25° tri-surface bevel: Three converging bevel surfaces create a true point rather than a single-blade edge, reducing penetration depth, lowering insertion force, and limiting tissue trauma.
• Universal NanoFil fit: Every needle is mounted on a standard 460 µm shank, so any NanoFil needle works in any NanoFil syringe, regardless of volume.
• Quick in-experiment swaps: A patented silicone gasket on the NanoFil syringe lets you switch needle gauges mid-experiment with negligible sample loss.
• Durable handcrafted tips: Each tip is penetration-tested before leaving the factory; the tri-bevel geometry resists dulling far better than single-surface bevels.
• Blunt and beveled options: Blunt tips for soft tissue and uniform distribution, beveled tips for penetration through tougher tissue (e.g. ocular, cardiac, dermal).

Which gauge should I choose?

The right gauge depends on the target tissue, injection volume, and sample viscosity. As a starting point:

• 26G — Front-filling the syringe; injections where speed matters more than tip footprint.
• 33G — General-purpose; comparable to Hamilton's 7762/7803 series but with a shorter, more durable tri-bevel tip.
• 34G — Intermediate option between 33G and 35G when one is too stiff and the other too fragile.
• 35G — The most popular size in WPI field trials; the best balance of strength, durability, clog resistance, and small footprint for mouse work.
• 36G — The smallest commercial gauge. Use only when absolutely necessary; the 25–50 µm tip ID clogs easily and the tip must be limited to ~3 mm length to maintain rigidity. Pre-loading with a larger needle and well-filtered samples are recommended.

Blunt or beveled — how do I decide?

Use blunt tips when injecting into soft tissue or when uniform sample distribution is the priority — the dead-ended bore prevents the directional bias a bevel can introduce. Choose beveled tips when the needle has to penetrate tougher tissue such as cornea, dura, or skin, or when reducing tissue damage at the injection site is critical.

Can I use any NanoFil needle with any NanoFil syringe?

Yes. Every NanoFil needle is mounted on a universal 460 µm shank, so all gauges are interchangeable across all NanoFil syringe volumes (10 µL and 100 µL). The patented silicone gasket on the syringe also allows mid-experiment needle swaps with negligible sample loss — useful for front-filling with 26G and then switching to a finer tip for the injection itself.

What's the difference between the 25° tri-surface bevel and a standard single bevel?

A conventional 10° single-surface bevel produces a blade-like edge, which dulls quickly and requires deeper tissue penetration to deliver sample at a target depth. WPI's 25° tri-surface bevel grinds three converging surfaces to create an actual point. The result is less penetration force, shallower required insertion depth, and a tip that holds its sharpness much longer. WPI's internal testing shows a 35G tri-bevel reduces required penetration depth by ~80% compared with a 33G single-bevel Hamilton needle.

Is the NanoFil Needles system available in Israel with local support?

Yes. NBT Ltd is the exclusive distributor of NanoFil and the full WPI microinjection range in Israel, providing local technical support, application advice on tip selection, and integration with stereotaxic and pump systems.