Noise reduction for microscopic images

I have these microscopic images that need to be analyzed based on the size, shape and color of the nuclei in the cells. I tried reducing the noise using a Median Filter, but when i binarized the image it looked terrible. What is the best method to reduce the noise in these images before analysis?

Image sample:

Note: the green spots are the ones being analyzed. The red color does not contribute to the analysis.

Thanks