The Utilization of dye extracted from hylocereus costaricensis (red dragon fruit) as a counterstain in gram staining / Joyce C. Ador Dionisio, Danycah Amor H. Amorio, Julia Mae R. Atega, Alyssa Baquir, Lourise Joyce V. Carreon, Joshua A. Carubanga, Alessandra Gabrielle M. Cristobal, Janiea G. Del Rosario, Cheyenne Kaye P. Espiritu, Lara Gwyneth M. Padamada and Martin Lawrence M. Punzal.

Includes appendices and bibliographical references.

Abstract: Environmental awareness has changed toward using naturally sourced color pigments in food items as alternatives for synthetic counterparts due to the growing toxicity of dyes employed in laboratories. One of those synthetic dyes that seriously irritates the eyes as well as the skin is safranin, a counterstain used in the Gram staining method. In this study, the researchers investigated the staining capability of the Hylocereus costaricensis (red dragon fruit) dye as a counterstain to Staphylococcus aureus and Escherichia coli, which is known gram-positive and gram-negative bacteria respectively using the routine Gram staining procedure. Two experiments were conducted as part of this research. Both experiments use the same extraction method, which is a crude extract, with the exception of the materials, the amount of Hylocereus costaricensis (red dragon fruit), and the solvents that were employed. The first experiment only used methanol as a solvent and Hylocereus costaricensis (red dragon fruit) peels to extract the dye. In contrast, in the second experiment, both the flesh and the peel of the Hylocereus costaricensis (red dragon fruit) were employed, and in addition to methanol, ethanol was used separately as a solvent. In order to extract the dye and test its staining capability, an experimental method was used. The staining potential of Hylocereus costaricensis (red dragon fruit) dye was then assessed using Gram staining method. The extracted dye extracts from both experiments showed an acidic pH, which ranged from 4.4 to 4.9. in each of the experimental samples, the researchers found that none of the extracted dye concentrations could stain the gram-negative bacteria (Escherichia coli) as evidenced by the fact that the stain obtained from Hylocereus costaricensis (red dragon fruit) did not adhere to the bacteria cell walls microscopically. As a result, the researchers concluded that the Hylocereus costaricensis (red dragon fruit) dye using a crude extraction method cannot be employed as a counterstrain in the Gram staining procedure.

Thesis - School of Medical Technology