(III) Our Accomplishment

  • What is the end product/ findings?
  • A description/ explanation of your product/ findings

- What colours do you see in the stained tissue?
- Describe the appearance of the tissue in terms of shape and cells
   and how they are arranged.

The hematoxylin will stain the nucleus and the eosin stained the cytoplasm. That is why in the picture above, the nucleus is purple and the cytoplasm is pink and a little light compared to the colour of the nucleus. Usually when we observe liver tissue, they should be firm and have many layers. However, in this case, the tissue has many gaps here and there. This is a abnormal behaviour of the cells and hence, there is a possibility of cancer. 

- What colour(s) do you observe?
The cells are stained with a pale blue-green precipitate, and there are certain areas with a darker streak of precipitate.
- What does the colour(s) indicate?
The presence of the precipitate indicates the presence of the protein - vimentin. When the enzyme from the second antibody bonds to the protein, it forms the precipitate, and thus when there is a greater amount of vimentin, the intensity of the precipitate is increased.


Fluorescence dye staining: Organelles such as the nucleus can be stained using fluorescence dyes. A special light source will enable the dye to fluorescence to indicate the location of the organelle.
The Hoechst dye are in the family of fluorescence stains labelling DNA.
The dye is excited by ultraviolet light, and emits blue/cyan fluorescence light.
- What colour do you observe in the stained tissue?
Fluorescent Blue.
- What organelle does the colour indicate?
Nucleus. The dye stacks itself in the DNA, which is located in the nucleus as the dye is class-specific and stains only the DNA, showing us where the nucleus is. 
  • Why is there a black background?
Since the dye only stains the nucleus, the other parts of the cell such as the cytoplasm cannot be seen with the UV light as it is not stained. 
The specimen is illuminated with light of a specific wavelength which is absorbed by the fluorophores, such as the Hoechst dye, causing them to emit light of longer wavelengths (i.e. of a different colour than the absorbed light). Hence, only the stained nucleus can be seen, and not the other parts of the cell.