Insulin Syringes (1ml 29G)

1ml / 100-unit insulin syringe, fixed 29G needle (12 mm) — red or pink

A 1ml (100-unit) insulin syringe with a fixed 30-gauge needle for accurately drawing and measuring reconstituted research material. Sterile and single-use, available in red or pink. Sold singly or in packs of 10.

Areas of research#

• 1ml / 100-unit barrel
• Fixed 29G needle (12 mm)
• Sterile, single-use
• Available in red or pink
• Sold singly or in packs of 10

Identity and specification#

Both colours are the same gauge and the same length, from two manufacturers: the pink is Unisharp, the red is Acufine. The practical difference is the grip — the pink has a wider plunger end disk and larger finger grips, the red a thinner needle wall and a scratch-off panel on the plunger for marking individual units apart. Either way the draw is through 0.33 mm.

We also stock a finer 30G B.Braun Omnican at the same 12 mm length, with a stated 0.5 µl dead volume. It wastes less and reads more easily; it draws more slowly. That page carries a side-by-side comparison.

Reading a 1 ml insulin syringe#

An insulin syringe is graduated in units rather than millilitres, and that is where most measuring errors in a lab start. On a standard U-100 syringe, 100 units occupy 1 ml, so one unit is 0.01 ml and the numbered marks are ten units apart. The barrel does not care what is in it: the scale measures volume, not quantity of peptide. Converting between the two is arithmetic the operator does, from the mass stated on the vial and the volume of solvent actually added.

That last phrase matters. The volume added is the volume measured into the vial, not the volume printed on the ampoule of solvent, and the two differ if any is left behind. Recording the real figure at reconstitution is what makes every later withdrawal from that vial meaningful.

Gauge, length and fixed needles#

Gauge describes the outside diameter on an inverted scale — 29G is finer than 25G, and the number climbs as the needle thins. Length is stated separately in millimetres. A fixed-needle syringe has the needle bonded permanently to the barrel, which removes the dead space of a detachable hub: less solution is stranded in the fitting and lost when the syringe is discarded. These are low-dead-space units specifically, so the volume left behind after the plunger bottoms out is smaller again — which matters most when what is in the barrel cost more per millilitre than the syringe did. The trade-off is that the needle cannot be changed independently, so a blunted or blocked needle means a new syringe.

Finer needles pass viscous solutions more slowly. Material reconstituted at high concentration, or drawn straight from refrigeration, will resist the plunger noticeably. Letting a vial return to room temperature first does more for a stiff draw than force does, and force is how barrels crack.

Drawing accurately#

• Draw a little past the target mark, then expel back to it — approaching from above leaves air behind
• Tap the barrel with the needle upward so bubbles rise to the hub before expelling them
• Read the graduation at eye level; reading at an angle is worth several units of parallax error
• Swab the vial stopper with a 70% isopropyl pad and let it dry before each entry
• One syringe, one withdrawal — then straight into a sharps container

Why they are single-use#

The needle point is ground and coated for one pass. After a single entry through a rubber stopper the bevel is measurably deformed under magnification, which makes the next entry harder and shears small fragments from the septum into the vial. Silicone lubricant on the plunger also depletes, so a reused syringe both drags and measures less repeatably. Reuse costs accuracy long before it becomes a contamination question, and it is a contamination question too.

Handling and storage#

Keep syringes sealed in their blisters, dry, at room temperature and out of direct light until the moment of use; the sterile barrier is the packaging, and a blister that has been opened, crushed or damp is no longer one. Do not autoclave or attempt to re-sterilise a disposable syringe — the plastic distorts and the lubricant migrates. Used units go into a rigid sharps container, which is disposed of through a licensed route, never through household waste.

Sizes and pricing#

Working with lyophilised peptides? See our pens, syringes and needles guide, reconstitution guide, storage guide and how to read a COA.