Standardization of blood smears prepared in transparent acetate: an alternative method for the microscopic diagnosis of malaria.

Fabio A Leal-Santos,Thamires M Gasquez,Francisco C Luz,Cor JF Fontes,Marcia BC Mello,Eduardo R Alves

doi:10.1186/1475-2875-13-238

Fabio A Leal-Santos, Thamires M Gasquez + Show 4 more

Open Access

https://doi.org/10.1186/1475-2875-13-238

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Abstract

BackgroundDue to students’ initial inexperience, slides are frequently broken and blood smears are damaged in microscopy training, leading to the need for their constant replacement. To minimize this problem a method of preparing blood smears on transparent acetate sheets was developed with the goal of implementing appropriate and more readily available teaching resources for the microscopic diagnosis of malaria.MethodsAcetate sheets derived from polyester were used to standardize the preparation and staining of thin and thick blood smears on transparent acetate sheets. Thick and thin blood smears were also prepared using the conventional method on glass slides. The staining was conducted using Giemsa staining for the thick and thin smears.ResultsMicroscopic examination (1,000x) of the thin and thick blood smears prepared on transparent acetate produced high-quality images for both the parasites and the blood cells. The smears showed up on a clear background and with minimal dye precipitation. It was possible to clearly identify the main morphological characteristics of Plasmodium, neutrophils and platelets. After 12 months of storage, there was no change in image quality or evidence of fungal colonization.ConclusionPreparation of thin and thick blood smears in transparent acetate for the microscopic diagnosis of malaria does not compromise the morphological and staining characteristics of the parasites or blood cells. It is reasonable to predict the applicability of transparent acetate in relevant situations such as the training of qualified professionals for the microscopic diagnosis of malaria and the preparation of positive specimens for competency assessment (quality control) of professionals and services involved in the diagnosis of malaria.

Highlights

Due to students’ initial inexperience, slides are frequently broken and blood smears are damaged in microscopy training, leading to the need for their constant replacement
The lack of qualified professionals to correctly diagnose malaria and the lack of quality control in the laboratory diagnostic process have been identified as the main reasons for the lack of success in the current strategy to control this disease in Brazil [4]
Five commercial acetates made of polyphthalate polycarbonate (PPC) or crystalline polyvinyl chloride (PVC) resisted treatment with methanol and were used in other standardization procedures

Summary

Introduction

Due to students’ initial inexperience, slides are frequently broken and blood smears are damaged in microscopy training, leading to the need for their constant replacement. To minimize this problem a method of preparing blood smears on transparent acetate sheets was developed with the goal of implementing appropriate and more readily available teaching resources for the microscopic diagnosis of malaria. The microscopic analysis of a thickly stained blood smear is still the most suitable method for the diagnosis of malaria. It is a simple, quick, low-cost technique that enables the correct diagnosis of the malarial parasite species and the determination of parasite density. The lack of qualified professionals to correctly diagnose malaria and the lack of quality control in the laboratory diagnostic process have been identified as the main reasons for the lack of success in the current strategy to control this disease in Brazil [4]

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