What Is the Difference Between Luer Slip & Luer Lock?

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Syringes with needles provide a method for administering medicine within the human body without the need for a patient to swallow the mixture. Syringes also remove bodily fluids, such as blood, for analysis. Many varieties of syringes have been developed as technology advanced, needs arose and innovations occurred.

Among the innovations were a couple of different methods of attaching needles securely but simply to the syringes. Luer slip needles and Luer lock needles offer two different attachment points for various medicinal uses.

Syringe History

H. Wulfing Luer developed an all-glass syringe near the end of the 1800s. In the 1950s, new technologies were emerging, such as radioisotopes (radioactive elements), prompting the development of more precise syringe parts for experimentation. Detachable needles, like Luer slip and Luer lock needles, provided flexibility for various applications in science and medicine.

Luer Slip

Luer slip needles simply slide onto a syringe's barrel or body. As the needle pushes onto the barrel, it fits snugly against the assembly, although it is not locked securely like a Luer lock-style needle is. The Luer slip needle type is common for less viscous medicine injections, such as vaccinations. It is also suitable for blood withdrawals for blood testing.

Luer Lock

Luer lock needles use a twisting motion for locking the needle tip to the barrel. This needle type is fixed upon the barrel, without the ability to slide off like the Luer slip. However, this locking mechanism makes the needle and barrel assembly safer for thick medicine injections. There is no possibility of the thick medicine separating the needle from the barrel due to high pressures during injection. Aspirating abscesses, full of thick pus discharge, require a Luer lock needle for moving the discharge from the patient to the syringe's barrel.

Health Safety

The separating ability of the Luer lock and Luer slip needles from syringe barrels provides a more thorough cleaning after use. Workers separate needles from barrels and place the needles in an alcohol solution for sterilisation. The barrels cannot be submerged in alcohol since the rubber plunger tip will become damaged from alcohol exposure. After sterilisation, both the needles and barrels are boiled for further decontamination. The separation of the parts allows more cleaning infiltration within the confined interiors of both the needle and barrel, producing a completely clean and sterile syringe for future use.


The needle's diameter is also an important consideration, along with the slip or lock assembly. Using a small-gauge, or small diameter, needle with a thick medicine may cause the needle to dislodge from the barrel or cause the patient pain, regardless of the slip or lock tip type. Medical professionals should verify gauge size and needle attachment types before injecting patients.