Archivos de Medicina Veterinaria, 37(2), 147-154.

Härtel, S., Rojas, R., Räth, C., Guarda, M. I., & Goicoechea, O. (2005).

Growing international competition is forcing salmon farmers to incorporate innovative techniques into the production process. The use of triploid, all-female breeding populations offers multiple advantages over diploid populations. Currently, an exact, simple, and non- hazardous method for the quantification of diploid- and triploid salmon erythrocytes does not exist. We present a method that combines a standard microscopic bright field technique (contrast staining with GIEMSA) with multi-parameter image analysis and termed it quantitative morphologic microscopy (QMM). We used flow cytometry (FC) as the reference method to determine the DNA content of di- and triplod erythrocytes from immature rainbow trout (Oncorhynchus mykiss). Additionally, we applied quantitative fluorescence microscopy (QFM), using the DNA stains 4′,6-diamidino-2-phenylindole (DAPI), propidium iodide (PI), and acridine orange (AO). Our data show that QMM possess comparable or even superior discriminating capacities than FC or QFM. The developed method opens a perspective for the classification of microscopic objects with many possible applications.