1. Introduction
Histology is a science which studies the normal microstructure of the human body and the relationship between the body’s structure and function. cells are the smallest structural and functional unit of human body

2. Key points of this class
Methods employed in Histology

3. 1. Histology 2. Embryology Histo=Tissue Logy=Study Logy= study
Embryo= unborn or unhatched offspring
Logy= study

4. What we will learn in this course
Tissue: 4 basic tissues
Organ system

5. Why it is important to learn histology?
To recognize normal tissue and cells
To acquire basic skill
which you will use throughout your career!!!

6. What you need to do
Look
Think
Compare
Remember
Idealized images

7. 2. Basic methods of histology
Observation of histological slides
Procedure:
Specimen Fixation Embedding
Sectioning Staining Observation

8. Fixation solution (fixative)
LM--- 4% formaldehyde – Fixative and
antibacterial agent
EM--- glutaraldehyde followed by osmium tetroxide

9. Embedding Ethanol----dehydration Xylene----clearing
Paraffin----embedding

10. Sectioning Microtome thickness 2~10 μm Units M,mm,μm,nm
1nm=0.001μm=10-6mm=10-9m

11. Microtome

12. Staining Basophilia , Acidophilia, Neutrophilia, metachromasia
Basic dyes: toluidine blue, methylene blue, hematoxylin (blue)
Acid dyes: orange G, eosin, acid fuchsin (pink)
common staining: Hematoxylin & Eosin
Specific staining: silver

13. Hematoxylin & Eosin (H&E)
H&E is the most commonly method in histological study
Hematoxylin Blue
Eosin Pink

14. Hematoxylin Eosin H&E

15. 3. Microscopes Light microscope Specific microscope
(1). Phase-contrast microscope
(2). Differential interference microscope
(3). Fluorescence microscope
(4). Confocal microscope

17. Electron microscope EM Transmission - plain
Scanning – platinum or gold layers, 3 dimensional

18. Photograph of the transmission electron microscope.

19. Schematic view of a transmission electron microscope with its lenses and the pathway of the electrons. CCD, charged coupled device.

20. Schematic view of a scanning electron microscope.

21. 4. Other methods A. Autoradiography
B. Histochemistry and cytochemistry
PAS (periodic acid Schiff reaction)
Feulgen reaction
C. Immunocytochemistry
Antigen and antibody reaction
D. In situ hybridization
DAN or RNA single strand complementary

22. Other methods (continue)
E. Cell culture —stem cells
F. Transgenic animal
G. Micromanipulation and cloning

24. Summary
1. Histology is the study of the tissues of the body and of how these tissues are arranged to constitute organs.
2. Histology=Microscopic anatomy
 3. Section preparation and HE staining 
4. Other methods