Mix / draw-up needle 3ml

The 3 ml transfer unit is a sterile laboratory consumable for volumetric work, technically consisting of a graduated polypropylene cylinder, an elastomer-sealed plunger, and a removable stainless steel cannula with a Luer connection. In scientific research, this type of unit is used to collect, mix, and transfer measured volumes of liquid between closed vials. The unit is offered with a cylinder capacity of 3 ml and a 0.8 × 40 mm cannula, exclusively for laboratory and research purposes.

What is the transfer unit of 3 ml?

The cylinder is manufactured from transparent polypropylene with a printed scale and is chemically inert to aqueous media and most polar liquids. The piston is sealed with an elastomer ring, so that the volume drawn is determined by the position of the piston and not by leakage along the wall. The head terminates in a conical Luer connection, allowing the cannula to be interchangeable and also accommodating membrane filters or adapters. The cannula is a thin-walled stainless steel tube measuring 0.8 × 40 mm.

The large inner diameter is the reason this design is chosen for larger volumes. Flow through a narrow tube approximately follows Hagen-Poiseuille's law: the volume flow increases with the fourth power of the inner radius. Consequently, a wider opening significantly reduces the required pressure drop, keeping the shear force on the fluid lower and reducing the amount of air introduced. This is relevant because foaming at the air-liquid interface promotes protein unfolding and air bubbles render volume measurements inaccurate. Therefore, within scientific research, the transfer unit is used as a standardized tool for volumetric and analytical work.

Research areas

In a laboratory context, a transfer unit of this type occurs in the following research areas, among others:

• Volumetric transfer and aliquotation of aqueous solutions between closed vials.
• Gravimetric verification of volume delivery against an analytical balance.
• Research into the adsorption of peptides to polypropylene and steel surfaces and the effect on sample recovery.
• Material compatibility study regarding extractable and leaching components upon contact with organic media.
• Sample preparation, including filtration over a Luer-coupled membrane filter prior to chromatography.
• Research into foam formation and shear sensitivity of macromolecules during flow through a narrow passage.

Each of these applications involves controlled laboratory or preclinical model research.

The transfer unit within our research range

Within our range, this unit falls under laboratory consumables: aids that support working with research compounds without being the subject of study themselves. While this unit fulfills a volumetric and mechanical function, other components within the same line have been selected to play a physico-chemical role, for example, the removal of residues. They share the status of an aid but differ in material, operating principle, and purpose.

Specifications

Shape, handling and storage

The unit is supplied individually sealed and is intended for single use. Pre-processing is not required: the cylinder and cannula are assembled and sterilized in packaging. The scale is intended for indicative volume determination; where higher accuracy is required, gravimetric control is preferred.

Store the packaging dry at room temperature, protected from light and mechanical stress. Do not use a unit with a damaged seal or an expired expiry date; sterility is then not guaranteed. Handle the unit with customary laboratory precautions: clean environment, suitable personal protective equipment, no reuse between different solutions, disposal via a sharps container, and out of reach of unauthorized persons.

Composition and lab results

For this article, the composition is expressed in material and dimensional specifications rather than as a purity percentage: a 3 ml polypropylene cylinder with a 0.8 × 40 mm stainless steel cannula. This choice of material determines the chemical resistance and the inertness of the surface towards the transferred medium.

You can find an overview of the available analytical documentation on our lab results page, where the reports are centrally collected.

Frequently Asked Questions

To which category does this article belong?
It is a sterile laboratory consumable for volumetric fluid transfer, not a chemical compound. Therefore, no CAS number or molecular formula can be assigned to it.

Why a wider passage for larger volumes?
Because the volume flow through a narrow tube increases with the fourth power of the inner radius, a wider opening reduces the pressure drop and thereby the shear force on the fluid.

Is the cannula replaceable?
Yes. The conical Luer connection follows standard dimensions, allowing the cannula to be replaced by an adapter or a membrane filter.

How do I store the units?
Dry, at room temperature and protected against light and mechanical stress, in the original sealed packaging.