Surgical glue, also known as tissue adhesive, is a sterile liquid used in medical settings as an alternative to traditional sutures or staples for closing wounds and incisions. This substance is precisely applied to the top layer of the skin, where it quickly hardens to form a strong, protective seal over the injury. Its use allows for faster wound closure and eliminates the need for a follow-up visit to remove stitches. The adhesive creates a flexible, water-resistant barrier that holds the edges of the skin together while healing takes place.
The Colors of Surgical Glue and Why Visibility Matters
Surgical glue is often manufactured with a noticeable color, most commonly blue, violet, or light purple. This color is not part of the adhesive’s functional chemistry but is an intentionally added dye. The purpose of this distinct pigmentation is purely practical: to improve the visibility of the liquid glue during application. Without a colorant, the clear liquid would be difficult for the medical professional to see against the patient’s skin, making precise placement challenging.
The dye ensures the surgeon or clinician can clearly track exactly where the adhesive is being spread, guaranteeing complete coverage and proper wound alignment. Colored varieties are preferred in many surgical and emergency settings to ensure accuracy. This visual aid is important for achieving a clean closure and a favorable cosmetic outcome, as the glue must bridge the wound without seeping into the deeper tissues.
How Tissue Adhesives Bond the Skin
Surgical glue is based on a family of compounds called cyanoacrylates, similar to the chemistry found in household “super glue.” Medical formulations are designed to be less toxic and more flexible than their industrial counterparts. These liquid adhesives are stored in a stable, monomer state until they are exposed to moisture, which acts as a chemical catalyst.
When the liquid contacts the natural moisture on the skin’s surface, a chemical reaction called anionic polymerization is triggered. This process rapidly links the small monomer molecules into long, solid polymer chains, creating a strong, flexible resin layer. The resulting polymer forms a durable bridge across the wound edges, holding them together. This hardened layer provides mechanical strength and functions as an effective microbial barrier, sealing the incision from external bacteria.
Post-Application Care and Natural Removal
Once the tissue adhesive has been applied, patients are given simple care instructions to ensure proper healing. It is important to keep the area clean and dry, especially during the first 48 hours, though gentle showering is usually permitted afterward. Patients must avoid scratching, rubbing, or picking at the adhesive, as premature removal compromises wound closure and increases the risk of infection.
A significant benefit of using surgical glue is that it does not require professional removal. The adhesive naturally stays in place long enough for the wound to heal, typically between five and ten days. The glue adheres only to the uppermost layer of the epidermis. As the outer skin layer constantly sheds dead cells, the hardened glue layer is gradually lifted and will flake off spontaneously. Patients should also avoid applying petroleum jelly, ointments, or lotions directly over the glue, as these can weaken the polymer bond and cause the adhesive to detach too soon.