staining.
For AO/PI staining, the Mn-treated and untreated Acanthamoeba cells were harvested and washed with PBS and
then incubated with 5μl of acridine orange (10μg/ml) and propidium iodide (10μg/ml) at a ratio of 1:1 in 1 ml of
cells and centrifuged at 1000 rpm/15 min. After centrifuge, supernatant was removed leaving 50 μl of residual
supernatant with pellet. The pellet was resuspended and 10 μl was pipetted on the slide before putting on the cover
slip. Within 30 min, the slide was analyzed using fluorescence microscope (Leica, Germany).
2.3 Analysis of DNA damage by Alkaline Comet Assay
Analysis of DNA damage by alkaline comet assay for Acanthamoeba sp. was performed after 2 h treatment with
Mn in six-well plates containing trophozoites (104 cell/ml) at their IC25 concentration. The alkaline comet assay
protocol described by Lah et al. [2] was followed. One hundred cells on each slide with three replicates were
viewed, classified and quantified based on descriptions by Collins [10]. Kruskal-Wallis Test was used to analyse the
data obtained from the comet scoring.
3. Results and discussion
Anthropogenic activities have led to metal pollution in the water bodies as it threatened some of the aquatic