English to Italian Medical Medical (general) Istologia

Secondo Wikipedia, lo "staining" è "a technique used to enhance contrast in samples, generally at the microscopic level." Ma in italiano come si chiama? Colorazione? Pigmentazione?

Il mio testo parla di uno studio clinico per sperimentare un farmaco anticancro:

**ER2 staining** is used by your healthcare team to work out which treatment option would be most beneficial for your type of cancer.
Patients with low or very low levels of HER2 staining are 2 of the 3 groups of staining classed by the medical profession as HER2-negative patients.