From the patient to the pathologist, the preparation of tissue samples for histological examination requires special care, skill and proper procedures.
This guide provides practical advice on sample processing techniques and summarizes best practices and suggests simple ways to avoid common mistakes. Each aspect of the histological process is described: sampling, slicing, processing in a technon, watering, slicing and staining (routine, special, immunohistochemistry and in situ hybridization).
We believe that each step described will provide you with valuable comments on good histological practice and help eliminate any problems that may occur during tissue processing.
Content
Click on the titles of the individual chapters to get to the detailed description of each step.
1. Sampling and transport of the sample
Step 1: Avoid mechanical damage
Step 2: Avoid drying the sample
Step 3: Avoid heat damage
Step 4: Avoid chemical damage
Step 5: Proper sample labeling
Step 6: Ensure rapid
Krok xaci Step 7: Use a suitable fi xation vessel
Step 8: Check the pH
Krok xativa Step 9: Accelerate fi xation of large samples
Step 10: Avoid unnecessary delays
Step 11: Handle samples with care
2. Cutting
Step 12: Check the condition fi xace
Step 13: Cut the samples into thin sections
Step 14: Avoid damaging the sample
Step 15: Avoid cross-contamination
Step 16: Use foam pads in the cassettes
Step 17: Select suitable cassettes
Step 18: Avoid overfilling the cassettes
Step 19: Clearly label cartridges
3. Processing in a tissue automaton
Step 20: The right program
Step 21: Follow-up
Step 22: Maintain the quality of solutions and paraffin
Step 23: Use high quality paraffin
Step 24: Avoid hazardous reagents
4. Tissue watering
Step 25: Correct sample orientation
Step 26: Select a suitable potting mold
Step 27: Handle specimens gently
Step 28: Avoid overheating
Step 29: Check temperatures regularly
Step 30: Do not overfill molds
5. Slicing
Step 31: Use good quality razor blades and knives
Step 32: Optimize the tilt angle of the knife
Step 33: Carefully cut the blocks
Step 34: Avoid frost damage
Step 35: Use cold blocks
Step 36: Cut slowly
6. Tensioning of sections
Step 37: Use clean water
Step 38: Ensure the cleanliness of the slides
Step 39: Avoid cross-contamination of samples
Step 40: Avoid contamination with skin cells
Step 41: Do not work with multiple blocks at the same time
Step 42: Check bath water temperature
Step 43: Avoid section summary
Step 44: Avoid excessive expansion of the sections
Step 45: Do not damage the section when tensioning
Step 46: Carefully select the sections
Step 47: Avoid bubbles under the section
Step 48: Increase the adhesion of the sections
7. Drying of slices
Step 49: Allow to drip before drying
Step 50: Monitor drying temperature
Step 51: Dry for a reasonable time
8. Routine staining (hematoxylin / eosin)
Step 52: Observe staining times
Step 53: Monitor quality regularly
Step 54: Standardize staining conditions
Step 55: Ensure proper deparation
Step 56: Change reagents regularly
Step 57: Thoroughly hydrate sections
Step 58: Monitor hematoxylin quality
Step 59: Ensure complete core staining – bluing
Step 60: Avoid uneven eosin staining
Step 61: Monitor eosin pH
9. Assembly, preparation of a permanent specimen
Step 62: Thoroughly drain the sections before clearing and mounting
Step 63: Prevent the section from drying out before mounting
10. Special dyeing
Step 64: Know what we want to see
Step 65: Use the positive control
Step 66: Observe staining times
Step 67: Check the stability of staining solutions
Step 68: Properly store staining solutions
Step 69: Follow the staining protocol exactly
Step 70: Record all changes
Step 71: Standardize the washing steps
Step 72: Carefully adjust the microscope
11. Immunohistochemistry (IHC)
Step 73: Use High Quality Sections
Step 74: Ensure Optimal fi xaci
Step 75: Avoid Problems with Section Adhesion
Step 76: Optimize Paraffin Removal and Reagent Use
Step 77: Avoid Concentration Gradients
Step 78: Carefully Select Antibody
Step 79: Read Antibody Instructions
Step 80: Optimize unmasking methods
Step 81: Consider antibody cross-reactivity
Step 82: Block endogenous peroxidases
Step 83: Prevent false background staining
Step 84: Use an appropriate detection system
Step 85: Standardize washing
Step 86: Optimize core staining
Step 87: Use appropriate control
Step 88: Evaluate the results carefully
12. In situ hybridization (ISH)
Step 89: Use high quality sections
Step 90: Ensure optimal
Krok xaci Step 91: Avoid section adhesion problems
Step 92: Optimize paraffin removal and reagent dosing
Step 93: Carefully select the hybridization probe
Step 94: Read probe instructions
Step 95: Optimize pretreatment
Step 96: Handle samples gently
Step 97: Use a suitable detection system
Step 98: Avoid evaporation of reagents
Step 99: Standardize washing
Step 100: Use a suitable control
Step 101: Evaluate results carefully