What is the primary action when excising a tissue lesion for a biopsy using a laser?

The primary action when excising a tissue lesion for a biopsy using a laser involves the interaction of the laser light with chromophores in the tissue, particularly melanin and hemoglobin. This is crucial because lasers are designed to target specific molecules within the tissue, which absorbs the laser energy. When the laser interacts with melanin, it helps in targeting pigmented lesions, such as moles or certain skin cancers. Similarly, hemoglobin absorption is important for vascular lesions, as the laser energy causes photocoagulation and tissue vaporization.

This specificity is what allows for precision in the procedure, minimizing surrounding tissue damage, reducing bleeding, and facilitating a cleaner excision. The efficiency of laser energy in cutting and coagulating tissue makes it the preferred method in many cases of tissue biopsy and excision.