Preparation of tissue sections using fluorescence-based detection
The present disclosure is directed to an improved method for distinguishing tissue from an embedding medium, such as paraffin in a formalin-fixed paraffin-embedded sample. The method involves the use of fluorescence of naturally-occurring species in tissue to determine the location of the tissue in the embedded sample. An embedded sample is generally excited by light of a selected wavelength, and the fluorescence emission at an emitted wavelength is used to locate the boundary or location of the tissue in the embedded sample.
1. A method to distinguish tissue from embedding medium, the method comprising:
irradiating an embedded tissue sample with light having a wavelength of from about 200 nm to about 600 nm, wherein the embedded tissue sample comprises a tissue and an embedding medium, and the tissue is optically indistinguishable from the embedding medium under normal lighting conditions; and
analyzing endogenous fluorescence emission of the embedded tissue sample.
2. The method of claim 1 , wherein the embedding medium is a paraffin.
3. The method of claim 1 , wherein the embedded tissue sample is a formalin-fixed paraffin-embedded (FFPE) tissue block.
4. The method of claim 1 , wherein the endogenous fluorescence emission is detected using an imaging device comprising a camera.
5. The method of claim 4 , wherein a digital image of the endogenous fluorescence emission is used to determine the location of the tissue in the embedded sample.
6. The method of claim 5 , wherein pixel intensity of the digital image is used to determine the location of the tissue in the embedded sample.
7. The method of claim 1 , wherein the method is used to determine a location of a tissue surface.
8. The method of claim 7 , further comprising slicing or trimming a section from the embedded sample after determining the location of the tissue surface.
9. The method of claim 8 , wherein the method comprises staining the section with at least one stain.
10. The method of claim 1 , wherein the light has a wavelength of from about 250 nm to about 450 nm.
11. The method of claim 1 , wherein the endogenous fluorescence emission is generated by autofluorescence of a component of the tissue.
12. The method of claim 11 , wherein the component is elastin or collagen.
13. A method to distinguish tissue from embedding medium in an embedded tissue sample, the method comprising:
providing an embedded tissue sample comprising a tissue and an embedding medium,
irradiating the embedded tissue sample with light having a wavelength of from about 200 nm to about 600 nm, and
analyzing endogenous fluorescence emission of the embedding medium.
14. The method of claim 13 , wherein the embedding medium is a paraffin.
15. The method of claim 13 , wherein the embedded tissue sample is a formalin-fixed paraffin-embedded (FFPE) tissue block.
16. The method of claim 13 , wherein the tissue is optically indistinguishable from the embedding medium under visible lighting conditions.
17. The method of claim 13 , wherein the tissue and the embedding medium are further distinguished by examining endogenous fluorescence emission from the tissue.
18. The method of claim 13 , further comprising determining a location of a tissue surface in the embedded sample.
19. The method of claim 18 , further comprising slicing or trimming a section from the embedded sample after determining the location of the tissue surface.