Histopathology techniques are used to demonstrate minute structural alterations in tissues caused by disease. Key techniques include fixing tissues in formalin to preserve structure, processing tissues through dehydration, clearing and infiltration steps, embedding in paraffin wax, sectioning with a microtome, staining, and mounting slides. Histopathology allows diagnosis of diseases through microscopic examination of tissue structures and any pathological changes present. It is a crucial technique when other testing may not be possible or provides definitive confirmation of diseases.
This presentation deals tissue processing in histopathology, the detailed of presentation given blow:
Histology, study the organization of tissues at all levels, from the whole organ down to the molecular components of cells that are found in most multicellular plants and animals.
Animal tissues are classified as epithelium, with closely spaced cells and very little intercellular space; connective tissue, with large amounts of intercellular material; muscle, specialized for contraction; and nerve, specialized for conduction of electrical impulses. Blood is also sometimes considered a separate tissue type.
Plants are composed of relatively undifferentiated tissue known as meristematic tissue; storage tissue or parenchyma; vascular tissue; photosynthetic tissue or chlorenchyma and support tissue or sclerenchyma and collenchyma.
This presentation deals tissue processing in histopathology, the detailed of presentation given blow:
Histology, study the organization of tissues at all levels, from the whole organ down to the molecular components of cells that are found in most multicellular plants and animals.
Animal tissues are classified as epithelium, with closely spaced cells and very little intercellular space; connective tissue, with large amounts of intercellular material; muscle, specialized for contraction; and nerve, specialized for conduction of electrical impulses. Blood is also sometimes considered a separate tissue type.
Plants are composed of relatively undifferentiated tissue known as meristematic tissue; storage tissue or parenchyma; vascular tissue; photosynthetic tissue or chlorenchyma and support tissue or sclerenchyma and collenchyma.
Histopathology is examination of tissues for presence or absence of changes in their structure due to disease processes. We go through various steps in the process of converting gross sample to microscopic slides.
Histopathology is examination of tissues for presence or absence of changes in their structure due to disease processes. We go through various steps in the process of converting gross sample to microscopic slides.
Histological techniques in fish disease diagnosis by B.pptxB. BHASKAR
Categories of techniques for Detecting presence or exposure to causative agents, Sampling methods for histopathology of fin fishes and shell fishes, Tissue fixation, staining, advanced serum proteomics, Advanced techniques for intelligence diagnosis of fish diseases.
Lung Cancer: Artificial Intelligence, Synergetics, Complex System Analysis, S...Oleg Kshivets
RESULTS: Overall life span (LS) was 2252.1±1742.5 days and cumulative 5-year survival (5YS) reached 73.2%, 10 years – 64.8%, 20 years – 42.5%. 513 LCP lived more than 5 years (LS=3124.6±1525.6 days), 148 LCP – more than 10 years (LS=5054.4±1504.1 days).199 LCP died because of LC (LS=562.7±374.5 days). 5YS of LCP after bi/lobectomies was significantly superior in comparison with LCP after pneumonectomies (78.1% vs.63.7%, P=0.00001 by log-rank test). AT significantly improved 5YS (66.3% vs. 34.8%) (P=0.00000 by log-rank test) only for LCP with N1-2. Cox modeling displayed that 5YS of LCP significantly depended on: phase transition (PT) early-invasive LC in terms of synergetics, PT N0—N12, cell ratio factors (ratio between cancer cells- CC and blood cells subpopulations), G1-3, histology, glucose, AT, blood cell circuit, prothrombin index, heparin tolerance, recalcification time (P=0.000-0.038). Neural networks, genetic algorithm selection and bootstrap simulation revealed relationships between 5YS and PT early-invasive LC (rank=1), PT N0—N12 (rank=2), thrombocytes/CC (3), erythrocytes/CC (4), eosinophils/CC (5), healthy cells/CC (6), lymphocytes/CC (7), segmented neutrophils/CC (8), stick neutrophils/CC (9), monocytes/CC (10); leucocytes/CC (11). Correct prediction of 5YS was 100% by neural networks computing (area under ROC curve=1.0; error=0.0).
CONCLUSIONS: 5YS of LCP after radical procedures significantly depended on: 1) PT early-invasive cancer; 2) PT N0--N12; 3) cell ratio factors; 4) blood cell circuit; 5) biochemical factors; 6) hemostasis system; 7) AT; 8) LC characteristics; 9) LC cell dynamics; 10) surgery type: lobectomy/pneumonectomy; 11) anthropometric data. Optimal diagnosis and treatment strategies for LC are: 1) screening and early detection of LC; 2) availability of experienced thoracic surgeons because of complexity of radical procedures; 3) aggressive en block surgery and adequate lymph node dissection for completeness; 4) precise prediction; 5) adjuvant chemoimmunoradiotherapy for LCP with unfavorable prognosis.
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New Drug Discovery and Development .....NEHA GUPTA
The "New Drug Discovery and Development" process involves the identification, design, testing, and manufacturing of novel pharmaceutical compounds with the aim of introducing new and improved treatments for various medical conditions. This comprehensive endeavor encompasses various stages, including target identification, preclinical studies, clinical trials, regulatory approval, and post-market surveillance. It involves multidisciplinary collaboration among scientists, researchers, clinicians, regulatory experts, and pharmaceutical companies to bring innovative therapies to market and address unmet medical needs.
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
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Knee anatomy and clinical tests 2024.pdfvimalpl1234
This includes all relevant anatomy and clinical tests compiled from standard textbooks, Campbell,netter etc..It is comprehensive and best suited for orthopaedicians and orthopaedic residents.
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
ARTIFICIAL INTELLIGENCE IN HEALTHCARE.pdfAnujkumaranit
Artificial intelligence (AI) refers to the simulation of human intelligence processes by machines, especially computer systems. It encompasses tasks such as learning, reasoning, problem-solving, perception, and language understanding. AI technologies are revolutionizing various fields, from healthcare to finance, by enabling machines to perform tasks that typically require human intelligence.
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New Directions in Targeted Therapeutic Approaches for Older Adults With Mantl...i3 Health
i3 Health is pleased to make the speaker slides from this activity available for use as a non-accredited self-study or teaching resource.
This slide deck presented by Dr. Kami Maddocks, Professor-Clinical in the Division of Hematology and
Associate Division Director for Ambulatory Operations
The Ohio State University Comprehensive Cancer Center, will provide insight into new directions in targeted therapeutic approaches for older adults with mantle cell lymphoma.
STATEMENT OF NEED
Mantle cell lymphoma (MCL) is a rare, aggressive B-cell non-Hodgkin lymphoma (NHL) accounting for 5% to 7% of all lymphomas. Its prognosis ranges from indolent disease that does not require treatment for years to very aggressive disease, which is associated with poor survival (Silkenstedt et al, 2021). Typically, MCL is diagnosed at advanced stage and in older patients who cannot tolerate intensive therapy (NCCN, 2022). Although recent advances have slightly increased remission rates, recurrence and relapse remain very common, leading to a median overall survival between 3 and 6 years (LLS, 2021). Though there are several effective options, progress is still needed towards establishing an accepted frontline approach for MCL (Castellino et al, 2022). Treatment selection and management of MCL are complicated by the heterogeneity of prognosis, advanced age and comorbidities of patients, and lack of an established standard approach for treatment, making it vital that clinicians be familiar with the latest research and advances in this area. In this activity chaired by Michael Wang, MD, Professor in the Department of Lymphoma & Myeloma at MD Anderson Cancer Center, expert faculty will discuss prognostic factors informing treatment, the promising results of recent trials in new therapeutic approaches, and the implications of treatment resistance in therapeutic selection for MCL.
Target Audience
Hematology/oncology fellows, attending faculty, and other health care professionals involved in the treatment of patients with mantle cell lymphoma (MCL).
Learning Objectives
1.) Identify clinical and biological prognostic factors that can guide treatment decision making for older adults with MCL
2.) Evaluate emerging data on targeted therapeutic approaches for treatment-naive and relapsed/refractory MCL and their applicability to older adults
3.) Assess mechanisms of resistance to targeted therapies for MCL and their implications for treatment selection
2. HISTOPATHOLOGICAL TECHNIQUES
• Histopathology is the branch of pathology which
concerns with the demonstration of minute structural
alterations in tissues as a result of disease.
• Most of histopathological techniques simulating to those of
applied for study the normal histological structures.
• For the demonstration of minute histological changes, the
tissue must be processed in such a manner that it will provide
maximum information.
• Most convenient way for study of morbid tissue is to use
permanent section.
• A section is prepared by cutting a thin slice from a small piece
of fixed tissue.
• Thin slice is mounted upon a glass slide in a medium of
suitable refractive index and covered with a glass slide.
3. Scope
• Though the histopathological techniques are labour intensive, cumbersome and
time consuming, particularly when there are automation equipments are not
available; however, their use in diagnosis of diseases is unequivocal.
• Some of the areas where histopathological diagnosis is helpful are described
as follows:
• This is useful in establishing the pathogenesis and pathology of any disease
caused by bacteria, virus, chlamydia, rickettsia, mycoplasma, parasite, toxin,
poisons etc.
• There are certain diseases in which histopathological examination of tissues is
the only alternative to diagnose the disease. e.g. Bovine spongiform
encephalopathy. The agent of this disease takes a very long incubation period and
very difficult to isolate and there is no immune response and inflammation in
animal. Therefore, histopathology remains the only alternative for confirmatory
diagnosis.
• In some cases, the tissues from dead animals are only available material for
laboratory diagnosis. This may occur either due to lack of time or due to
negligence for not collecting the material for serological tests or isolation studies.
Sometimes the transportation of material from remote areas destroys the other
material and the tissues fixed in formalin only remains for making diagnosis. In all
such cases the histopathological examination has its pivotal role.
4. • The histopathological procedures produce permanent slides, which can be
stored for a longer period and one cannot manipulate the findings; therefore,
it is considered best reliable technique.
• The histopathological techniques are useful in carrying out the
retrospective studies. The unstained slides and blocks can be stored for
indefinite period; which can be examined even after many years for further
studies.
• The presence of causative agents can also be demonstrated in tissue
sections using routine histopathological techniques or special stainings. In
this Gram's staining procedures are used for demonstration of bacteria while
viral inclusions are demonstrated using hematoxylin and eosin or other
staining techniques like Macchiavello's stain or Mann's methylene blue
eosin method. The Negri bodies are demonstrated by Seller's stain in
case of rabies in animals. In such cases, the isolation of causative agent or
their serological examination does not require; since the presence of
causal agent in infected tissues gives a confirmatory diagnosis.
• The detection of chemicals in tissues like enzymes, lipids etc. is
included in histochemical examination; which not only describe the structural
changes but also gives idea about the functional status of the organ.
5. Collection of Samples:
1. Small piece of tissue (as early as possible)
2. Piece is removed with sharp knife in a particular orientation.
3. Size of piece=1cm to achieve better penetration of fixative.
4. Washing the specimen with normal saline to achieve maximum penetration
of fixative.
5. At the time of tissue collection, it should be kept in mind that the
representative tissue piece should include the part of lesion and a part of
normal tissue,
6. Tissue pieces for histopathological examination should be collected from
all the organs.
7. Tissues should be collected directly in the fixative and not in any other pot
or water.
8. The tissue pieces from hollow organs like intestines, oviduct etc should be
cut transversely and placed on a hard paper.
9. The representative tissue should not be collected from such damaged
portions.
10. The tissues from encapsulated organs should be collected alongwith
capsule or covering.
Labelling:
• Tissue is accompanied by a tag or label, bearing the lab. number given to
specimen at start, through all stages.
• Thin white card with writing in soft pencil withstands all the fluids used in
tissue processing.
Sample collection and preservation
6. Fixation:
• Hardening of the organ in such a way that its
original form is retained and its constituents do
not spread out while cutting.
• Small block of tissue is immersed in Neutral
Buffered formalin 10% (at least 10 times the
volume of tissue)
Properties of Fixation
• Preserve protoplasm with least alterations
(autolysis, bacterial decomposition)
• To kill the cells suddenly, uniformly(life like
manner)
• It coagulates the cell proteins and intercellular
bodies in a life position.
• It prevent cell from shrinkage and deleterious
effect of cutting.
• Facilitate proper staining.
• Preserve tissue from drying.
7. Commonly used Fixatives
• 10% Formalin Solution.
• Buffered Neutral Formalin Solution.
• Formalin Alcohol. (glyogen, good cytoplasmic fixation)
• Zenker Fluid. (bone marrow aspirates)
• Bouin’s Fluid. (embryological specimens, Purkinje cells)
• Acetone. (Rabies)
• Ethyl Alcohol. (glycogen, pigments, amyloid, hylaine,
elastic fibers and bacteria)
• Glacial acetic acid. (rapid fixation, swelling of cells)
• Potassium Dichromate. (cytoplasm, not nucleoproteins)
• Heat. 5-10 mm thick piece of tissue, boil in 0.9 percent
Nacl solution for 2-3 min.
8. 10% Formalin Solution
37%-40% Formaldehyde 100 ml
Distilled water 900 ml
Neutral buffered formalin
37%-40% Formaldehyde 100 ml
Distilled water 900 ml
Sodium Phosphate monobasic 4 gm
Sodium Phosphate dibasic (anhydrous) 6.5 gm
9. Trimming of tissue
• Tissue, enclosed in tissue cassette
and placed in basket of automatic
tissue processor.
Washing of the Tissue
• Washing of tissue under running
tape water overnight (12 hours)
remove excessive Fixative Solution.
10. PROCESSING
Dehydration
•The purpose of dehydration to remove fixative and
water from the tissue and replace them with
dehydrating fluid.
•There are a variety of compounds many of which are
alcohols. Several are hydrophilic so attract water from
tissue.
Types of dehydrating agents:
•Ethanol
•Methanol
•Acetone
11. • To minimize tissue distortion from diffusion currents, delicate
specimens are dehydrated in a graded ethanol series from
water through 10%-20%-50%-95%-100% ethanol.
Ethyl alcohol 70% 2 hour
Ethyl alcohol 80% 1 hour
Ethyl alcohol 95% 1 hour
Ethyl alcohol (Absolute 1) .5 hour
Ethyl alcohol (Absolute 2) .5 hour
• To increase the process of dehydration, the tissue blocks
should be agitated either mechanically in an automatic tissue
processor or by shaking the container periodically.
• The volume of alcohol should be at least 50 times more than
the tissue placed for dehydration.
12. Clearing:
• It involves removal of dehydrating agent and replacement by
some fluid which is miscible with dehydrating agent and
embedding medium.
Choice of a clearing agent depends upon the following:Choice of a clearing agent depends upon the following:
• The type of tissues to be processed, and the type
of processing to be undertaken.
• The processor system to be used.
• Intended processing conditions such as temperature,
vacuum and pressure.
• Safety factors.
• Cost and convenience.
• Speedy removal of dehydrating agent .
• Ease of removal by molten paraffin wax .
• Minimal tissue damage .
13. • Like ethanol, xylene should also be kept in tightly
stoppered bottle to prevent the evaporation.
Equal parts of Absolute alcohol +Xylene .5 hour
Xylene I 1 hour
Xylene II 1 hour
• If xylene is not available then benzene may be used for 3
hr as its action of clearing is slower than xylene.
• On complete clearing, the tissue becomes transparent,
then they should be transferred in paraffin wax for
impregnation.
14. Wax Impregnation/Infiltration
•It is the process by which tissues are
surrounded by a medium such as agar,
gelatin, or wax which when solidified will
provide sufficient external support during
sectioning.
•Tissue is impregnated with melted wax.
•Xylene +Paraffin 1 hour
•Paraffin wax I 2 hours
•Paraffin wax II 3 hours
15. BLOCKING/ EMBEDDING
• At the time of transfer of tissue blocks
from xylene II, the paraffin wax must
be kept at (60-62°C) in liquid form at a
temp. 2 or 3 above the melting point .
• For impregnation/dispension into
mould to depth more than adequate to
cover the tissue block.
• The tissue is introduced with warmed
forceps.
• As soon as a film of solid has formed
on the surface
• Submerged beneath cold water to
hasten solidification of wax.
16. MICROTOMY
• Paraffin blocks are cooled before
sectioning.
• The section thickness is adjusted at
15µm to trim away any surplus wax and
to expose a suitable area of tissue.
• On exposing the suitable area, thickness
is set at 2-5um.
• Sections adhere to each other to
produce a ribbon.
• First section is held with fingers or
forceps and the last being detached by
means of a small camel hair brush.
17. FLOATING &PICKING UP SECTIONFLOATING &PICKING UP SECTION
• The ribbon is floated on the water
surface heated at 45 C, with the
trailing end of the ribbon making
contact with the water first.
• The ribbon may be split into
individual or group of sections by
the use of forceps
• Picking up a section on a slide is
achieved by immersing the slide
vertically in the water to three
quarter of it’s length
18. DRYING SECTIONSDRYING SECTIONS
• The slides are placed on the hot
plate adjusted at melting point of
wax for ten minutes.
• Drying in oven at the same
temperature should be done for 45
minutes.
19. PRE STAINING PREPARATIONPRE STAINING PREPARATION
Deparaffinization with XyleneDeparaffinization with Xylene
• Xylene IXylene I 3 minutes3 minutes
• Xylene IIXylene II 3 minutes3 minutes
RehydrationRehydration
• Absolute ethyl alcoholAbsolute ethyl alcohol II 3 minutes3 minutes
• Absolute ethyl alcoholAbsolute ethyl alcohol IIII 3 minutes3 minutes
• Ethyl alcohol 90%Ethyl alcohol 90% 2 minutes2 minutes
• Ethyl alcohol 70%Ethyl alcohol 70% 2 minutes2 minutes
• Distilled waterDistilled water 3 minutes3 minutes
• Wash in tap water and rinse in Distilled waterWash in tap water and rinse in Distilled water
20. STAININGSTAINING
• Harris haematoxylinHarris haematoxylin 15 min15 min
• Distilled waterDistilled water 5 min5 min
• Acid alcohol 70%Acid alcohol 70% 4-10 dips4-10 dips
• Ammonia AlcoholAmmonia Alcohol 5 min5 min
• Wash in running tap waterWash in running tap water 5 min or less5 min or less
• EosinEosin 2 min2 min
• Wash in running tap waterWash in running tap water 1-5 minutes1-5 minutes
21. POST STAINING PROCEDURESPOST STAINING PROCEDURES
• Ethyl alcohol 95%Ethyl alcohol 95% 2 min2 min
• Ethyl alcohol 95%Ethyl alcohol 95% 2 min2 min
• Absolute Ethyl alcoholAbsolute Ethyl alcohol 2 min2 min
• Absolute Ethyl alcoholAbsolute Ethyl alcohol 3 min3 min
• Xylene IXylene I 3 min3 min
• Xylene IIXylene II 3 min3 min
23. Eosin solutionEosin solution
• EosinEosin 1 gm1 gm
• Distilled waterDistilled water 100 ml100 ml
• Acetic acidAcetic acid 0.05 ml0.05 ml
Acid alcohol:Acid alcohol:
• Ethyl alcohol 70%Ethyl alcohol 70% 990 ml990 ml
• HCl (concentrated)HCl (concentrated) 10 ml10 ml
Dilute ammonia solutionDilute ammonia solution
• Distilled waterDistilled water 250 ml250 ml
• Ammonia (concentrated)Ammonia (concentrated) 2 drops2 drops
24. • Acid dyeAcid dye: When the staining property is in: When the staining property is in
the acid radical of the neutral salt, thethe acid radical of the neutral salt, the
stain is called an acid dye e.g.,stain is called an acid dye e.g., eosineosin,,
picric acid, azo dyes, tryan red, orange G.picric acid, azo dyes, tryan red, orange G.
• Basic dyeBasic dye: The coloring property is in the: The coloring property is in the
basic radical of the neutral salt, the stain isbasic radical of the neutral salt, the stain is
called a basic dye e.g.,called a basic dye e.g., hematoxylinhematoxylin,,
toluidine blue, methylene blue.toluidine blue, methylene blue.
25. PRECAUTIONSPRECAUTIONS
• Rapid fixation of fresh specimen is essential as post-
mortem degeneration markedly alters the appearance of the
various cell types in tissue making interpretation
unrewarding.
• Quality of nuclear staining begins to deteriorate and
precipitate is formed in stored stain after a few months. At
this stage, stain should be filtered and staining time should
be increased.
• It is better to prepare a fresh batch of stain every month
Preparation of Haematoxylin:
• Haematoxylin is dissolved in the absolute alcohol
• Alum is dissolved in the warm distilled water
• Haematoxylin solution is added to the alum solution and
rapidly brought to boil
• Mercuric oxide is then added
• Stain is rapidly cooled by plunging the flask into cold water
and acetic acid is added when cold
26. MOUNTINGMOUNTING
• Mounting with canada balsam,Mounting with canada balsam,
apply coverslip and examine underapply coverslip and examine under
the microscope.the microscope.
27. HELPFUL HINTSHELPFUL HINTS
• Lenses of your microscope should be cleanLenses of your microscope should be clean
• Make sure that fine adjustment knob is near the middle of its range ofMake sure that fine adjustment knob is near the middle of its range of
rotationrotation
• To start your observation using the lowest power objectiveTo start your observation using the lowest power objective
• By knowing the app. dia. Of RBC in the section, you can estimate theBy knowing the app. dia. Of RBC in the section, you can estimate the
size of other tissue components.size of other tissue components.
• Goat: 2.4 umGoat: 2.4 um
• Dog: 4.9umDog: 4.9um
• Chichen: 9.4umChichen: 9.4um
• Average value based on total of 20-30 cell measured from differentAverage value based on total of 20-30 cell measured from different
slide preparationsslide preparations
28. ARTIFACTSARTIFACTS
FoldFold
Knife marksKnife marks
SpacesSpaces
Stain precipitatesStain precipitates
ShrinkageShrinkage
Air bubblesAir bubbles
examples of commonly occurring imperfections seen inexamples of commonly occurring imperfections seen in
slide preparationsslide preparations
29. STAIN PRECIPITATESSTAIN PRECIPITATES
• Occasionally , solutionOccasionally , solution
accumulate precipitate thataccumulate precipitate that
may stick to the surfacemay stick to the surface
tissue section duringtissue section during
staining procedurestaining procedure
30. SEPARATION (SPACES)SEPARATION (SPACES)
• Tissue may be subjected toTissue may be subjected to
excessive pressure, tensionexcessive pressure, tension
or shrinkage duringor shrinkage during
processing resulting inprocessing resulting in
separations of tissueseparations of tissue
31. KNIFE MARKSKNIFE MARKS
• Caused by defects in theCaused by defects in the
microtome knife or bymicrotome knife or by
accumulation of debris onaccumulation of debris on
the knife edgethe knife edge
32. FOLDSFOLDS
• Folds occurs when theFolds occurs when the
tissue sections fail to spreadtissue sections fail to spread
properlyproperly