Sperm identification using Diff Quick, Gram, Panoptic and Papanicolaou stains and their application in Forensic Investigation

Abstract

Introduction: At present there is an increase in sexual crimes in the country, and many remain in impunity because they have not been reported or are reported late, since the victims are afraid to report the fact so as not to be revictimized during the crime. legal process. The expert work in forensic biology begins with the taking of a sample from the victim and the analysis of biological samples, which focuses on the investigation of semen or spermatic fluid, which could have been left both in the victim and in the place of the event, and the microscopic search continues to visualize spermatozoa using the specific "Christmas Tree" stain. Methodology: The purpose of the research was to validate the Diff Quick, Gram, Panopticon and Papanicolaou stains as alternative techniques for the identification of spermatozoa and their application in forensic investigation. The design was experimental since the test parameters are intentionally manipulated and it compares the staining’s described with the gold standard Christmas Tree test. The seminal fluid samples belong to voluntary patients who attend the San Juan Riobamba General Hospital, in the period September - October 2022. Results: The results were based on the quality of the microscopic image that allowed establishing the advantages and disadvantages of each of the tests. A significant statistical difference was found between the sensitivity of the experimental tests (p-value < 0.05). The Diff Quick and panoptic stains showed greater sensitivity in the identification of spermatozoa, in these stains a greater size of the spermatozoon head was also observed, and they showed a slightly dirty extended background compared to the other stains. Conclusions: Experimental tests show greater sensitivity in Diff Quick and Panoptic staining, but Gram and Papanicolaou could be used for this purpose because good morphological definition of spermatozoa is achieved.