What Is a Conical Centrifuge Tube? Types & Uses

Last verified: October 6, 2026. A conical centrifuge tube is a capped laboratory tube with a cylindrical upper body and a tapered, cone-shaped bottom, designed to hold liquid samples and to withstand the forces of a centrifuge. It is one of the most common consumables in any biology, chemistry, or clinical laboratory. Labs often call it a “conical tube” or, informally, a “Falcon tube,” after a brand name that became shorthand for the whole product category.

The tapered bottom is the defining feature, and it is there for a reason. When a sample is spun, anything denser than the surrounding liquid — cells, precipitated protein, debris, beads — is driven to the bottom of the tube. A conical tip concentrates that material into a small, compact pellet at the very point of the cone, which makes it easier to see, easier to separate from the liquid above it (the supernatant), and easier to resuspend afterward. A flat-bottomed tube would spread the same material across a wide area and make a loose, hard-to-handle smear.

This page is general educational information, not clinical, laboratory, or safety training. Always follow your institution’s procedures and the manufacturer’s instructions for the specific tubes and equipment you use.

What a Conical Centrifuge Tube Is Made Of and How It Is Built

Most conical tubes in everyday research use are molded from clear or translucent plastic. The two plastics you will meet most often are polypropylene, which is the usual choice for general work because it tolerates a wide range of solvents, resists breakage, and handles the stress of spinning well, and polystyrene, which is very clear and rigid but more brittle and less tolerant of many chemicals. Glass conical tubes also exist and are used where chemical resistance or heat tolerance matters more than convenience, but they are heavier, break more readily, and are generally reserved for specific applications.

Several design details are worth recognizing when you read a catalogue or a purchase request:

• Graduations. Most tubes carry printed volume markings along the side, useful for approximate measurement. These marks are a convenience, not a precision measurement; if exact volume matters, a pipette or a calibrated vessel is the right tool.
• Writing area. A frosted or printed patch lets users label the tube with a marker, which matters more than it sounds in a lab handling dozens of near-identical samples.
• Caps. Screw caps are standard. Some are flat-topped so the tube can stand on its cap; some are designed to seal tightly to limit leaks and aerosols. Whether a given cap is truly leak-proof under pressure or during transport depends on the product design, so it is a specification to check rather than assume.
• Skirted or non-skirted bases. Some tubes have a molded base that allows them to stand upright on a bench. Standard conical tubes without that feature need a rack to stay upright.
• Sterility. Tubes are commonly supplied pre-sterilized in sealed sleeves or bags, which is important for cell culture and microbiology; non-sterile bulk packs cost less and suit work where sterility is not required.

Common Sizes

Two sizes dominate: the smaller 15 mL conical tube and the larger 50 mL conical tube. Many labs stock both. The smaller size is convenient for modest sample volumes, small cell pellets, and serial steps in a protocol; the larger size handles bigger volumes such as culture harvests, buffer preparation, and bulk collection. Beyond these two, you will find smaller conical-bottomed tubes in the microcentrifuge range (often called microtubes) and some larger-capacity conical bottles for high-volume centrifuges. Which sizes fit your equipment depends on the rotor or adapters in your centrifuge, so size and equipment have to be matched.

Who Uses Conical Centrifuge Tubes, and Why

Conical tubes are used almost everywhere a laboratory handles liquid samples. Typical uses include:

• Pelleting cells and particles. Cultured cells, bacteria, yeast, and precipitates are spun down so the liquid can be removed or replaced. This is a routine step in cell culture and in preparing samples for downstream analysis.
• Separating components of a mixture. Spinning separates materials by density, so the same tube can be used to isolate a solid from a liquid or to layer and separate different phases.
• Collecting and holding samples. Because the tube is capped and graduated, it doubles as a general-purpose container for transferring, mixing, and short-term storage of reagents and samples.
• Preparing solutions and media. Buffers, diluted reagents, and small batches of culture medium are often made directly in conical tubes.
• Transporting samples within a facility. Capped tubes in racks or secondary containers move samples between benches, rooms, and instruments.

Clinical and diagnostic laboratories use similar tubes, and research core facilities often stock them by the case. Anywhere biology, chemistry, or medicine involves a liquid sample, a conical tube is likely nearby.

Types of Conical Tubes

Although they look similar, conical tubes are not interchangeable in every situation. The main variations are:

• Standard polypropylene tubes are the general-purpose workhorse for most routine centrifugation and storage.
• Polystyrene tubes offer clarity and are common for applications where viewing the contents matters, but they are not the best choice for high-speed spinning or for aggressive solvents.
• Glass conical tubes are used when chemical resistance, reuse, or heating are needed, and when plastic would interact with the contents.
• Low-binding tubes have treated surfaces designed to reduce the amount of protein, nucleic acid, or other material that sticks to the walls. They matter when working with scarce or dilute samples.
• Specialty tubes include those with filter inserts, with built-in separation media, or with light-protecting amber coatings for light-sensitive contents. These are application-specific products and the supplier’s documentation defines what they are designed to do.

The practical lesson is that the right tube depends on the sample, the solvent, the speed, and the downstream use. Reading the manufacturer’s specifications, rather than choosing on appearance alone, avoids many avoidable problems.

How a Conical Tube Differs From Adjacent Labware

• Microcentrifuge tube. A microcentrifuge tube holds a much smaller volume, usually spun in a small bench-top microcentrifuge. The conical tube holds larger volumes and is spun in a larger centrifuge fitted with the right rotor or adapters.
• Test tube. A standard round-bottomed test tube is a general container and is not designed to withstand centrifugal force. Using one in a centrifuge that is not rated for it is a hazard, so the tube’s rated use matters.
• Centrifuge bottle. Larger bottles hold much bigger volumes for high-capacity rotors and are built for that purpose; a conical tube is the smaller, more flexible format.
• Culture flask or bottle. These are meant for growing or storing larger quantities of culture and are not shaped to pellet material.
• Pipettes. A pipette is the instrument that measures and transfers liquid; the conical tube is a container the pipette often draws from or dispenses into.

Practical Notes for Research-Administration, Procurement, and Lab-Management Readers

Conical tubes are inexpensive per unit but are bought in large quantities, so small decisions add up and the details have real operational consequences.

• Match the tube to the equipment. A tube that does not fit the centrifuge’s rotor or adapter, or is not rated for the speeds the lab uses, is a safety and equipment-damage risk. See how to choose a centrifuge for how rotors and tube formats relate.
• Sterile versus non-sterile. Paying for sterile tubes where sterility is unnecessary wastes budget; buying non-sterile tubes for cell culture risks contamination and lost work. The cost difference is real, so the decision should follow the workflow.
• Single-use plastic and waste. Conical tubes are typically disposable. That creates plastic waste and, where samples are biological or chemical, regulated waste-handling obligations. Institutional waste policies govern how used tubes are disposed of. Some labs ask whether tubes can be sterilized and reused; whether a particular plastic tolerates that depends on the material, as discussed in which plastics are autoclavable, and an autoclave is not appropriate for every tube.
• Chemical compatibility. Not every plastic tolerates every solvent. Check the supplier’s compatibility information before storing or spinning anything other than aqueous solutions.
• Labeling and sample tracking. Many labs run on handwritten labels, which smear and fade. Where sample identity is critical, a labeling and tracking process matters more than the tube itself.
• Supply continuity. Because tubes are consumed daily, a stock-out can halt work. Standardizing on a small set of products simplifies ordering and reduces variability between experiments.

The Short Version

A conical centrifuge tube is a capped, cone-bottomed tube, most often polypropylene, in common sizes such as 15 mL and 50 mL. The cone gathers spun material into a compact pellet, and the screw cap and graduations make it a general-purpose container as well. Its job in a lab is to hold, spin, mix, and carry liquid samples. The details that matter for buyers and managers are material, sterility, cap design, and whether the tube is rated for the centrifuge and chemicals in use.

Frequently Asked Questions

What is a conical centrifuge tube used for?

It is used to hold liquid samples and to separate their contents in a centrifuge. Typical tasks include pelleting cells, separating solids from liquids, preparing solutions, and transporting or briefly storing samples.

Why is the bottom of the tube cone-shaped?

When the tube is spun, denser material moves to the bottom. The cone gathers that material into a small, compact pellet at the tip, which makes it easier to see, to separate from the liquid, and to resuspend.

What is the difference between a conical tube and a Falcon tube?

“Falcon tube” is a brand name that many people use informally for any conical centrifuge tube of this style. Functionally, the term describes the product type; the specifications of an individual product, not the label people use for it, determine what it is rated for.

Can I use any plastic tube in a centrifuge?

No. Tubes must be designed and rated for centrifugation and must fit the rotor or adapter. A tube that is not built for the forces involved can crack or leak, so check the manufacturer’s specifications and your centrifuge’s instructions.

Are conical tubes reusable?

Most are sold as single-use consumables. Whether a given tube can be cleaned, sterilized, and reused depends on its material and the manufacturer’s guidance, and many institutions simply require disposal after use, particularly where samples are biological or hazardous.

Are conical tubes sterile?

Many are supplied sterile in sealed packaging, and others are sold non-sterile at lower cost. Product labeling states which, so check before using one for cell culture or other sterile work.