Test Tube with Side Arm

Quick Answer: A Test Tube with Side Arm is a glass tube fitted with a small side-neck outlet near the top, used to connect vacuum or gas tubing while the main tube holds a liquid or reaction mixture, commonly for small-scale filtration and gas-collection setups.

Description

The Test Tube with Side Arm from LabEquip is a glass vessel similar in shape to a standard test tube, but with an additional narrow side outlet moulded into the upper wall of the tube. This side arm allows rubber or silicone tubing to be connected directly to the vessel, making it possible to apply vacuum or draw off evolved gas without disturbing the main opening at the top.

This design is useful wherever a small, sealed reaction or filtration vessel needs a secondary connection point — for example, holding a Buchner funnel or filter arrangement under gentle vacuum, or collecting gas released during a reaction while keeping the main mouth of the tube free for a stopper, dropping funnel, or delivery tube.

Because it is made of laboratory glass, the tube can generally tolerate the moderate heating and common laboratory reagents typical of teaching and general chemistry work, while the side arm keeps tubing connections neat and away from the main working opening.

Specifications

Applications

• Small-scale vacuum filtration where the side arm is connected to a vacuum line
• Collecting or venting gas evolved during a reaction carried out in the main tube
• General chemistry demonstrations that require a sealed vessel with a secondary tubing connection
• Teaching setups illustrating gas laws, pressure, or simple distillation and filtration principles

Care & Handling

• Support tubing connected to the side arm so that its weight does not put strain on the glass joint.
• Inspect the side-arm neck for cracks or chips before use, since this is the most stress-prone part of the tube.
• Clean and dry the tube thoroughly after use, rinsing the side arm as well as the main body.
• Store upright in a rack to protect the side arm from being knocked or chipped.

Why Choose LabEquip

LabEquip supplies test tubes with side arms alongside a wide range of lab glassware and general chemistry lab equipment for schools, colleges, and teaching laboratories. Our team can help you confirm the right size and side-arm configuration for your filtration or gas-handling setup. For bulk orders, institutional procurement, or technical questions about this product, please contact us and our team will assist promptly.

Frequently Asked Questions

What is a Test Tube with Side Arm used for?

It is used for small-scale vacuum filtration and gas evolution work, where the side arm connects to vacuum or gas tubing while the main tube holds the sample or reaction mixture.

How is the side arm connected?

The side arm is fitted with standard rubber or silicone tubing, which is typically run to a vacuum source or a gas collection setup.

Can the main opening still be used for a stopper?

Yes, the main opening remains free for a stopper, dropping funnel, or delivery tube while the side arm handles the vacuum or gas connection separately.

Is this test tube suitable for heating?

Laboratory glass test tubes with a side arm can generally tolerate the moderate heating typical of teaching chemistry work; please confirm specific heating limits for your application at enquiry.

What sizes are available?

These tubes are supplied in standard laboratory sizes. Please confirm the exact capacity and side-arm bore you require when you enquire.

How should the tube be cleaned and stored?

Clean and dry the tube and side arm thoroughly after use, inspect the side-arm neck for damage, and store upright in a rack to prevent chipping.

Last Updated: September 2026