Glass Capillary Tubing w/ Internal Glass Fiber (500/pk)

GD-1:  $210.81 - Ships in 1-5 days
Narishige's GD-1 are special borosilicate glass capillary tubes, 90 mm in length, and have been pre-washed in an ultrasonic bath. Each capillary has a glass filament (approximate diameter of 100 µm) attached to the inner wall. The narrow interface between the circumferences of the fiber and the glass tube dramatically increases capillary action. This allows for easy back-filling of micro-capillary needles by simply inserting the back of the needle into a drop of liquid. Enhanced capillary action carries the liquid all the way to the needle tip in about 1-3 minutes.


Q: How many capillaries are in a pack of GD-1?
A: A package of GD-1 has 500 tubes per pack whereas the sterile ultrasonically cleaned version of GD-1, GDC-1 and has 200 tubes per pack.

Keep in mind that for use with most needle pullers, depending on your use, the needle puller will pull each microcapillary into two distinct needles, so a package of 500 microcapillaries will allow you to create 1000 needles.

Q: What does the GD-1 look like? Where is the filament and how does it work?
A: GD-1, similar to the G-1 and GC-1 glass capillaries, looks just like a thin glass tube. But for the GD-1 there is a microscopic glass filament "rod" (like a thread) welded in place on the inside wall of the capillary. The interface of the rod and the inside of the tube increases capillary action making it easier to fill your capillaries.

image of needle cross-section
Cross-section of micro-capillary needles

When you pull the GD-1 with a needle puller, everything is one piece of glass, and it pulls together. The filament becomes thinner and "disappears", as the tip becomes smaller.

Outer Diameter : 1.0mm
Inside Diameter : 0.6mm
Internal Filament : Yes
Sterilized : No
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