Brush, Micro

Quick Answer: The Brush, Micro is a very small laboratory cleaning brush with a fine bristle head, used for narrow bores and small parts: glass tubing, side arms, stopcock bores, micro test tubes and the crevices of small apparatus. A micro brush for narrow tubes reaches places where even the narrowest test-tube brush will not fit.

Cleaning Where Other Brushes Cannot Go

Many pieces of glassware have narrow passages: the side arm of a filter flask, the delivery tube of a gas generator, the bore of a stopcock, the stem of a funnel or the inside of a small sample vial. Residue in these places is easy to miss and can block flow or contaminate the next experiment. A micro brush has a tiny head of fine bristles, often on a thin twisted wire, sized for these openings. The diameter, length and bristle material of this brush are not specified in the listing, and the size should match the smallest bore you need to clean.

Micro brushes also help with small instruments. Used dry, they clear dust and dried salt from the crevices around balance pans, electrode housings and the threads of screw caps without introducing liquid. Because the bristles are fine, they are more flexible than those of larger brushes, and pushing too hard bends the wire rather than cleaning faster. For standard test tubes and bottles, a larger brush such as the general cleaning brush is quicker.

Care & Handling

• Insert the brush with a twisting motion and withdraw it the same way; pulling sideways bends the fine wire.
• Never force the brush into a bore that is too narrow, since a stuck brush may crack the glass.
• Rinse the brush and let it dry straight; a kinked micro brush will not pass through narrow tubes.
• Keep micro brushes in a tube or pot so the fine heads are not crushed in a drawer.

Typical Cleaning Jobs

• Cleaning the side arms of filter flasks and distillation flasks.
• Clearing glass delivery tubes and bent tubing after gas preparation practicals.
• Brushing stopcock bores and the stems of funnels.
• Cleaning micro test tubes and small vials in microscale chemistry.
• Removing dust and crystals from balance surrounds and the threads of screw caps.

Specifications

Why Choose LabEquip

Micro brushes are bought by teaching labs running microscale chemistry, by analytical labs with small-bore glassware and by technicians who maintain instruments. LabEquip lists this brush in the General Lab Products range; tell us the bore sizes you need to reach on the contact page.

Frequently Asked Questions

What can a micro brush clean?

Narrow passages and small parts, such as side arms of flasks, delivery tubes, stopcock bores, funnel stems, micro test tubes and small vials, as well as crevices in apparatus where dust or crystals collect.

Can it clean capillary tubes?

Capillary tubes are usually too narrow for any brush. They are cleaned by drawing solvent or detergent solution through them, or are treated as single-use items, as with melting-point capillaries.

Is a micro brush safe to use on a balance?

A dry, clean micro brush is a common way to remove spilt powder from around a balance pan and from crevices. Switch the balance off first and never use liquid near the weighing mechanism.

How do I avoid bending the fine wire?

Twist the brush gently in and out of the bore instead of pushing straight or pulling sideways. If it meets resistance, withdraw it and soak the item longer rather than forcing it.

Should the micro brush be used wet or dry?

Use it wet with detergent solution for glassware, followed by rinsing. Use it dry for dust and loose crystals on instruments and electrical parts.

What if a bore is still blocked after brushing?

Soak the item in a solvent or solution that dissolves the blockage, then flush it with water from a wash bottle. Do not try to push the blockage through with a wire, which can crack the glass.

Last Updated: September 2026