Técnica de tinción de estructuras fúngicas con colorantes vegetales como una alternativa no contaminante

a number of chemical products are used to stain fungal structures. many of them are harmful to the health and highly contaminant to the environment, such as phenol. in order to avoid the use of these products, a staining technique was developed to stain fungal structures by using vegetable soluble stains which are used in food industry such as allura red no40 (16035) and bright blue no 1 (42090). to prepare the mixture of each stain, 1 ml of allura red or bright blue was used mixed with acetic acid (10 ml), glycerin (15 ml) in 75 ml of sterile distilled water. to slide preparation, several types of fungi and chromista that grew on natural substrate or agar media were used. the mounting prepared with allura red and bright blue were compared to stain used in the routine fungal diagnostic such as blue aniline and acid fucsin in lactophenol. the staining technique developed with allura red and bright blue allowed to observe, with high contrast, several fungal and chromista structures. besides, the technique is confident, cheap and non toxic, with high capacity of staining and durability. the technique constitutes a good alternative to didactical purpose and it is not contaminant because the reagents are innocuous to the human and environment.