Fluorescent Staining of Breast Biopsies

Breast biopsies were stained with fluorescent dyes DRAQ5 (Biostatus, LTD) and Alcoholic Eosin-Y 515 (Leica) to replicate the standard histological stains of hematoxylin and eosin [29 (link)]. The samples were individually submerged in 200 μL of a 50 mM solution of DRAQ5 in PBS (Fischer Scientific) for three minutes, then immediately submerged in 1 mL of PBS to rinse the excess stain. The biopsy was then submerged in 200 μL of a 50% w/v solution of Alcoholic Eosin-Y 515 in ethanol (Leica) for 10 seconds. Finally, the sample was dipped in 1 mL of 1% Surgipath acid Alcohol (Leica) to remove the excess Eosin-Y 515 stain and blotted on a fresh KimWipe (Kimberly-Clark) to absorb the excess liquid from the biopsy. The stained and lightly dried biopsy was mounted between two 0.15 mm D x 24 mm W x 50 mm L coverglass slides with gentle pressure for imaging.