Which needle gauge is typically used for intradermal injections?

Intradermal injections are performed to deliver a substance just beneath the surface of the skin, and choosing the right needle gauge is essential for this procedure. The 25 gauge needle is commonly used for intradermal injections because it strikes a balance between being fine enough to minimize tissue trauma while still having sufficient rigidity to ensure accurate placement of the needle and medication.

A finer gauge, like a 30 gauge, could potentially be too small, which may lead to difficulty in injection and could increase the risk of clogging, although it might be used for very specific cases or in very thin-skinned animals. On the other hand, a larger gauge like 18 or 22 is typically reserved for intramuscular or subcutaneous injections, where a larger volume or deeper injection is required. These needles would create more trauma to the tissue, which is not ideal for the more superficial placement required in intradermal injections.

Therefore, the 25 gauge needle stands out as the correct choice for intradermal injections due to its appropriate size for this specific application in laboratory settings.