This is the first time I did an H&E staining, and I found that there are some white (blank) spaces between the cells. I do not think this is the normal morphology of this tissue.

Here are two screenshots of the tissue. They are from exactly the same microscope slide, both of them are mouse heart tissue, and I think most of the cells in the picture are cardiomyocytes. They are 2 consecutive slices from a frozen cryotome.

My own opinion is:

1. I don't think these are adipose tissue.

2. In both screenshots the longitudinal muscle (top part) looks alright. The transverse muscle (bottom part) in picture 1 has white spaces, while the transverse muscle (bottom part) in picture 2 is normal. I am wondering if it is because some of my operations has damaged the tissue? and the transverse muscle is more prone to the damage(?)

This is the protocol that I followed:

1. Do fresh frozen sectioning;

2. Submerge the slide in 100% MeOH at -20 degree celcius for 30 min;

3. Remove slide, let MeOH evaporate;

4. Stain with hematoxylin for 3 min, wash by dipping in beaker with water for 15 times. Repeat with another beaker of water.

5. Stain with buffered eosin for 1 min, wash by dipping in beaker with water for 15 times. Repeat with another beaker of water.

6. Airdry.

Could anyone please tell me what might be wrong?