1. Artifacts in Histological Preparations

2. Microwave heating It’s a kind of low power energy carried by micro-waves Internal direct heating is our advantage It’s a physical effect, neither chemical nor magical

3. Perception Reality Microwaves cook my samplesMicrowaves create physical heat like conventionals do, but internally in the tissues. Better homogenity & efficiency. Rapid processing = poor morphology Today’s technology makes 12-14 hours an inefficient use of time. Quality is guaranteed priority. Antigens will be lost foreverDiagnostic equivalence is validated by studies showing optimal antigen reactivity. Molecular studies are not possibleMicrowave do not affect DNA, RNA and proteins’ quality at all. Day processing is uselessDay processing = same day diagnosis = patient centric care

4. 1.Samples Preparation Artifacts

5. Heat Damage Fig.1 Breast biopsy Damage from laser-generated heat or over-heated wax or while drying slides: loss of nuclear and cytoplasmic detail connective tissue fibers become coagulated

6. Crush Artifact Fig.2 Section of lymph node Damage from crushing by forceps or other surgical instruments: darkly staining distorted cell nuclei some stretching and flattening of tissue

7. Postmortem Change Fig.3 Section of liver Autolysis for delay of fixation: poorly defined nuclei imprecise cytoplasmic staining

8. Specimen Marking Dyes Fig.4 Skin biopsy Excision margins marked with coloring agents: not natural color of the margins possible penetration into the tissue

9. 2.Fixation Artifacts

10. Zonal Fixation Fig.5 Section of liver Different degrees of fixation at different levels within the specimen: insufficient time in fixative specimen too large reagent with poor penetration rate

11. Streaming Artifact Fig.6 Section of liver Precipitation and displacement of glycogen by an advancing fixation front

12. Formalin Pigment Fig.7 Red cells in a section of kidney Reaction of non-buffered (pH acid) formalin with hemoglobin: pigment as a brown to black associated with red blood cells

13. Mercury Pigment Fig.8 Section of kidney Fixation in mercuric chloride-containing fixatives: random brown to black granular deposits

14. 3.Tissue-Processing Artifacts

15. Vessel Shrinkage Fig.9 Section of brain stem Poor brain fixation: perivascular shrinkage membrane separation

16. Poor Processing Fig.10 Breast specimen Inadequate fixation, too short processing cycle, inappropriate or exhausted reagents, mechanical fault with the processor, wrong replacement of solvents: extensive loss of architectural detail and clarity disruption within loose connective tissue

17. Imcomplete Dehydration Fig.11 Gastrointestinal biopsy Incomplete dehydration during processing: loss of nuclei details cloudy appearance of sections

18. Under Decalcification Fig.12 Section of bone Inadequate decalcification: appearance of dark blue areas with hematoxylin in the trabeculae

19. Over Decalcification Fig.13 Sections of bone Excessive decalcification: loss of all nuclear detail distruction of tissue morphology

20. 4.Staining Artifacts

21. Residual Wax Fig.14 Section of skin Incorrect dewaxing prevents solutions penetration: presence of areas totally absent of stain

22. Incomplete Staining Fig.15 Section of liver Inadequately filled staining dish: absence of stain in some area of the section

23. Nuclei Not Crisp Fig.16 Section of skin Incomplete fixation or residual water after dehydration: “smudgy” or not crisp nuclei no distinct chromatin patterns

24. Thanks