An ink composition for marking a tissue specimen is provided. The inkcomposition has a general formula of 30.0 wt.% to 54.0 wt.% of an alkali soluble styrene； 0.3 wt.% to 1.7 wt.% ethylhydroxyethyl cellulose； 8.0 wt.% to 35.0 wt.% colorant； 0.0wt.% to 13.0 wt.% pigment； 23.0 wt.% to 47.0 wt.% deionized water； 0.35 wt.%to 1.65% defoamer and.1 wt.% to 1.1 wt.% preservative.The inks in accordance with the invention may have a peak transmission in thevisible spectrum at a wavelength of fromC322nm to 716nm or having a lineal UV-Vis spectrum with no visible peaktransmission between 250 nm and 950 nm. When appliedto a tissue specimen the ink compositions do not bleed onto adjacent tissuemargins. When view under a microscope the color of theink compositions can be distinguished from each other.
