ABSTRACT
· AIM:To compare the effect of fixation and select the optimal fixation solution and condition for PAS staining of guinea pig eyes among three different fixation solution:4％ paraformaldehyde solution,4％ glutaraldehyde solution and Davidson solution.· METHODS:Totally 30 healthy guinea pigs were divided into 6 groups:Group Ⅰ-Ⅱ were fixed in 4％ paraformaldehyde solution and 4％ glutaraldehyde solution for 24h,respectively;Group Ⅲ-Ⅴ were fixed in Davidson solution for 3,6 and 24h,respectively;and Group Ⅵ were fixed in Davidson solution for 3h and then transferred into 10％ neutral formaldehyde solution for 48h.All groups were sectioned by routine section method and undergone PAS staining,and then observed by light microscope.· RESULTS:It was found that the group which was fixed by Davidson solution for 3h,remained the most complete structure for PAS staining (Group Ⅲ).While the effect of fixation for the group which was transferred into 10％ neutral formaldehyde solution for preserving for 48h after fixing in Davidson solution for 3h was also acceptable for PAS staining (Group Ⅵ).The retinal cells remained clear and in order for both groups which was mentioned above.· CONCLUSION:The best fixation condition for PAS staining for eyes of guinea pigs is fixation in Davidson solution for 3h among these fixation conditions,while it is also suitable to transfer the eyes into neutral formaldehyde solution after fixing in Davidson solution for 3h for preserving for long periods,which is not severely reduced the effect of fixation for PAS staining.
ABSTRACT
Objective To compare the effects of three kinds of fixative solutions on paraffin section of mouse lens tissue and optimize the fixing?method of paraffin section in mouse lens tissue. Methods Three kinds of conventional fixatives were selected for the test ,including the conven?tional Davison’s solution,modified Davison’s solution and 10%neutral buffered formalin. Mice eyeball tissues were fixed with three different fixa?tives,embedded,sliced and then stained with HE method. The paraffin slices were observed under the light microscope. Results The structures of lens and retina fixed in conventional Davison ’s fixative solutions were clear and intact ,and the cells were arranged regularly and compactly. There was no eyeball distortion,contraction and retinal detachment in the eyeballs fixed in modified and conventional Davison’s fixative solution. However,the ones fixed in 10%neutral buffered formalin showed eyeball distortion and contraction,space and spherules. Conclusion The mice lens slides made from tissues fixed by conventional Davison ’s fixative solution are better than fixed by modified Davison ’s fixative solution and the 10%neutral buffered formalin fixed ones.
ABSTRACT
Las técnicas de fijación y conservación anatómica son realizadas habitualmente con soluciones que contienen formol, dado su bajo costo. Estas tienen varias desventajas como el olor irritante, rigidez, cambios de coloración de las estructuras, así como toxicidad con potencial cancerígeno, teratogénico y mutagénico para quien lo manipula. Por esto, es deseable utilizar soluciones sin formol. El objetivo de este trabajo fue comparar 2 métodos de conservación cadavérica, uno con formol (solución de Montevideo) y otro sin formol (método de Prives) utilizando la placenta humana como órgano experimental, evaluando sus parámetros macroscópicos. Se utilizaron 46 placentas humanas de partos normales y gestación a término. Las placentas fueron separadas en dos grupos (n=22 y n=24 respectivamente). El primer grupo de placentas fue perfundido con una solución con formol y el segundo grupo en una solución sin formol. Luego ambos grupos fueron sumergidos y mantenidos en sus soluciones respectivas por dos semanas y posteriormente retiradas dejándolas al aire a temperatura ambiente por 2 semanas más. Se analizaron las variables cuantitativas de peso y diámetro en cada una de las piezas, así como las variables cualitativas de consistencia, color, olor y crecimiento de micro/macro organismos. La recopilación de datos fue realizada previo al lavado, a los 14, 21 y 28 días. Los resultados mostraron que las placentas conservadas con el método de Prives presentaron mejor conservación en relación a su diámetro, consistencia, color y menor olor irritante en relación a las placentas tratadas con solución con formol. En ningún caso hubo crecimiento de micro o macroorganismos. En conclusión, emplear soluciones alternativas que sustituyan ventajosamente al formol como la fórmula de Prives conservan mejor las características macroscópicas de las placentas sin generar un olor irritante, deteniendo el proceso de descomposición.
The fixation and conservation techniques of anatomic material are commonly performed with solutions containing formaldehyde, given its low cost. These have several disadvantages such as the irritating odor, stiffness, discoloration of the structures, toxicity, carcinogenic, teratogenic and mutagenic risk for those who are exposed. Therefore it is desirable to use solutions without formaldehyde. The aim of this study was to compare 2 methods of anatomical conservation, one with formalin (Montevideo's solution) and one without formalin (Prives method) using the human placenta as an experimental organ model evaluating its macroscopic parameters. We used 46 human placentas from normal deliveries and term pregnancy. The placentas were separated into two groups (n=22 and n=24 respectively). The first group of placentas was perfused with formaldehyde solution and the second group in a solution without formaldehyde. Then both groups were immersed and maintained in their respective solutions for two weeks and then withdrawn leaving the air at room temperature for 2 weeks. Quantitative variables were analyzed for weight and diameter of each piece, and qualitative variables as consistency, color, odor and growth of micro/macro organisms were evaluated. Data collection was performed prior to washing at 14, 21 and 28 days. The results showed that conserved placentas with Prives method showed better conservation in relation to its diameter, consistency, color and less irritating odor in relation to placentas treated with formalin solution. In no case was growth of micro or macro organism. In conclusion, using advantageously at alternative solutions to formaldehyde, as the formula of Prives method, better preserved macroscopic characteristics of placentas without generating an irritating smell, stopping the decomposition process.