Abstract:
Background: Staining is a vital technique in clinical microscopy that enhances the contrast of
cellular elements during morphological examinations. Although synthetic dyes are extensively
used in staining biological samples, they were reported to be associated with potential adverse
effects on laboratory personnel and the environment. Recent studies have extensively documented
the possible usage of plant-derived dyes in staining biological tissues due to their affordability,
safety and biodegradability.
Objective: To evaluate the staining potential of a natural dye from Mirabilis jalapa on human red
blood cells (RBCs)
Methods: This was a laboratory-based experimental study. The magenta colour flowers of M.
jalapa were collected and cleaned with tap water. Then, they were subjected to drying in an oven
at 40°C and ground into a dry powder. 20 g of dry plant material was mixed with 100 mL of
double distilled water and incubated at 70°C in a water bath for 4 hours and subsequently at 25°C
for 12 hours. The extract was filtered through gauze and centrifuged at 5000 rpm for 15 min. The
supernatant was filtered using Whatman No.1 filter paper, evaporated by a rotary evaporator and
redissolved in distilled water. A serial concentration of dye solution was prepared and applied for
10 min on blood smears fixed by absolute methanol and observed under oil immersion. The
photographs taken by a digital microscope were subjected to intensity measurement using ImageJ
version 1.54f and statistically compared with Leishman stain by unpaired t-test using SPSS
version 18.0.
Results: Results demonstrated that dyes extracted from M. jalapa exhibit a staining potential on
human RBCs in a concentration-dependent manner. Furthermore, the ImageJ analysis revealed
that 80 mg/mL of M. jalapa dye has the potential to give optimal staining on RBCs with an
intensity of 116.82±0.53, which is almost comparable to Leishman stain (I=116.43±0.29,
p=0.151).
Conclusion: The dye obtained from M. jalapa demonstrated a staining potential on human RBCs;
however, further purification studies are recommended to establish this dye as an alternative
natural stain for RBCs.
