Part 1: General pathology

what methods do we have in IHC? (2)

- direct: using 1 labeled ab - indirect: uring several ab that leads to amplification of signal

late changes of postmortem changes: 4 (biological)

1. (autolysis) 2. putrification 3. saponification 4. mumification

4 types of biopsies:

1. Exicion 2. inscisional 3. core needle 4. fine needle aspiration

who determines if a patient is brain dead

1. GP, neurologist, anesthesiologist 2. check twice with 12 hours between each test

what is traditional pathology divided into? (3)

1. General pathology 2. Systemic pathology 3. Oncopathology

What dyes do we have? 26

1. H&E 2. congo red 3. toulidine blue 4. lugouls solution 5. PAS (periodic acid-schiff) 6. alaline blue 7. Van gieson's 8. masson's trichrome 9. orecien 10. gomori 11. oil red 12. sudan black 13. osmium tetraoxide 14. gram's 15. ziehl-neelsen's 16. giemsa 17. grocatt's silver 18. luxol fast blue 19. bielschowsky's silver 20. feulgen reaction 21. alkaline phosphatase 22. acid phosphatase 23. ATPase 24. IH 25. PTAH 26. PEARLS

what dye do we use to stain carbohydrates: 2

1. PAS 2. alaline blue

what dye do we use to stain connective tissue: 4

1. Van gieson's 2. masson's trichrome 3. orecein 4. gomori

what is important to remember when obtaining material? 2

1. adequate size of tissue 2. not teared, burnt or squashed

what do we use to stain enzyme histochemical stains: 3

1. alkaline phosphatase 2. acid phosphatase 3. ATPase

what is positive in excisional biopsy? (2)

1. all the tissue is available 2. it is a one step procedure for benign lesions, and fully treated by treatment

the methods in pathology (4)

1. autopsy 2. biopsy 3. cytology 4. or by different approach which is much more important

techniques for obtaining specimen (3)

1. autopsy 2. surgical pathology 3. analysis

what is cytogenetics used for?

1. chromosomal numerical abnormalities: Downs syndrome (trisomy 21), klinefelter syndrome (trisomy 46), turner syndrome (monosomy 45) and spontaneous abortion 2. chromosomal structural abnormalities: translocation (philadephia t 9:22), deletions, insertions 3. cancer (amplification, translocation, deletion, inversion)

what stains do we use to stain amyloid? 3

1. congo red 2. toluidine blue 3. lugouls solution

physical changes of early postmortem changes: 7

1. cooling 2. palor 3. dryness 4. postmortem spots 5. hypostasis 6. diffusion of fluid 7. diffusion of gas

what do we use IHC for? (5)

1. detection of linage specific antigen (e.g., immunostain (vimentin for mesenchymal tumors, CD34, endothelial marker, S-100 for melanoma) 2. typization of neoplasms (PSA, CEA, ALP, GIST: CD117) 3. prognostic markers in cancer (proto oncogene HER-2/neu overexpression in ca breast, tumor suppressor genes: p53, growth factor receptors: EFRG, tumor cell proliferation markers: Ki67, proliferation cell nuclearantigen: PNCA) 4. detection of infections: viral proteins (HPV, CMV, HBV), bacteria (H.pylori), parasites (pneumocystis carnii) 5. used in diagnosis and treatment of cancer

negative sides of frozen section biopsy: 1

1. difficult to obtain section of 4 micrometers

what 4 components of disease does pathology address?

1. etiology 2. pathogenesis 3. morphological changes 4. clinical manifestation

negative sides of incisional biopsy: 3

1. expensive 2. wound complications 3. poor technique compromises definitive surgery

what is the cooling of the postmortem changes

1. external factors: temp, moisture, flow of air 2. internal (body) factors: body volume, body temp before death, nutritional status, cooling begins 1-2 hours after death and drop with approx. 1C per 1 hours. complete cool body ca 10 hours after death

how do we transport the biopsy:4

1. glass, plastic or metal container 2. labeled with name, date of birth, date of obtained material, what tissue/organ 3. use gause to prevent the attachment of tissue 4. either fresh state (immediately at 4C or frozen perioperative biopsy) or in fixative solution (most commonly formalin)

what dyes do we use to stain microorganisms: 4

1. gram's 2. ziehl-neelsen's 3. giemsa 4. grocott's silver

what does the PCR cycle consist of? (3 steps)

1. head denaturation of DNA (at 94C for 60-90 sec) 2. annealing of the primers to their complementary sequences (at 55C for 30-120 sec) 3. extension of the annealed primers with DNA polymerase (at 72C for 60-180 sec) - repeated cycling can be done in automated thermal cycler and yields large accumulation of the target sequence since each newly generated product, in turn, acts as template in the next cycle.

negative sides of FNA: 4

1. hematomas 2. infections 3. pneumothorax 4. dissemination of tumor

positive sides of incisional biopsy: 2

1. it is the GOLD STANDARD 2. Excess tissue

negative sides of core needle biopsy: 2

1. limited sample 2. higher error rates (5-10%)

drynes postmortem changes

1. loss of water from body surface: skin, mucosa 2. opacity of cornea 3. dryness of lips

what do we use to stain neural tissue: 2

1. luxol fast blue 2. bielschowsky's silver

positive sides of FNA: 3

1. no anaesthesia is required 2. quick, safe and painless 3. inexpensive

Palor postmortem changes

1. normal color grey-pale. 2. pathological conditions: icteric, cyanotic color

what is the process of when sampling a biopsy and fixing the specimen: 9

1. obtaining material 2. transport 3. fixation 4. decalcification (sometimes) 5. dehydration and clearing 6. embedding 7. cutting 8. mounting 9. staining

what stains lipids? 3

1. oil red 2. sudan black 3. osmium tetraoxide

subdivision of pathology: (8)

1. pathological anatomy 2. pathological physiology 3. molecular pathology 4. histopathology 5. clinical/surgical pathology 6. immuno pathology 7. trasplantation immunity 8. immunopathology of neoplasia

Steps in IHC analysis (5)

1. permeabilization of cell, make it easier for antibody to attach, uses a mild detergent 2. blocking, reduced chance of nonspecific binding 3. primary antibody is incubated with epitope of antigen, formation of ab-ag complex 4. secondary ab incubation, binds to FC region of primary ab 5. visualization by fluoroscence microscope/light microscope

postmortem changes: postmortem blood clots

1. postmortem denaturation of blood proteins. 2. postmortem clot: soft consistency, shiny, do not adhere to part of vessel 3. thormbus: firmer (rough) and adheres to walls of vessel 4. autolysis:

steps in FISH (6)

1. protease treatment to get rid of all proteins, we are detecting the mRNA 2. left for overnight probe hybridization, but specific probes 3. probe bound to mRNA, show the location of the mRNA 4. washes to get rid of excess probes 5. add enzyme linked antibody that binds to probe 6. add substrate that make a color reaction (enzyme-substrate (E-S) reaction) other way is by fluroscently labelled antibodies FISH and it will tell you roughly how much mRNA is present but not quantitavly tell you how many copies (use PCR)

positive sides of core needle biopsy: 3

1. rapid 2. inexpensive 3. few complications

chemical changes of early postmortem changes: 3

1. rigor mortis 2. postmortem clots 3. autolysis

positive sides of frozen section biopsy: 3

1. since its frozen, no need for dehydration and clearing 2. quick and rapid 3. minimal shrinkage compared to paraffin

postmortem spots

1. starts ca 2 hours after death, complete after ca 8 hours after death. 2. 8 hours after they are movable, from 2 days they can be pushed out- 0 contrast to hematoma, from 3 days not 3. normal color= red-violet 4. light red indicated CO poisoning, freezing 5. dark red indicated HCN poisoning 6. dirty-brownish indicate methemoglobin poisoning 7. well visible: suffocation, chronic heart failure 8. bad visible: anemia

postmortem changes: rigor mortis

1. starts ca 2 hours, complete after ca 8 hours, end ca 2 days after death. 2. occurs faster in hot, and slower in cooler environments 3. stronger in robust body, tetanus, and strychin poisoning and weaker in smaller body, kachexia, sepsis 4. Nysten-Rule statement: continual from lower ATP organs to higher ATP organs- from head to feet. involuntary muscle first: heart, upper eyelids, neck, jaw, face, upper extremities, muscles of the trunk, lower extremities. 5. inversion N-R statement: from feet to head

why do we do fixation and with what?

1. to protect the tissues from digestion by enzymes or bacterial contamination 2. prevent post-mortem changes chemical fixative solutions: 10% formalin, alcohol (most common) physical fixation: frozen

clinical criteria for brain death: 11

1. unresponsive coma (no reflex movements) 2. no spontaneous respiration 3. no pain reflex 4. absent occulo-cephalic reflex (eye movements opposite to head direction) 5. no ocular responses with dilated 6. no corneal reflex (blinking of eye when cornea is touched) 7. no caloric reflex (test of vestibulo-ocular reflex that involves irritating cold/warm water/air to external auditory canal) 8. no laryngeal and cough reflex 9. fixed pupuls 10. isoelectric (flat) EEG 11. confirming test indicating absence of cerebral circulation

negative side of excisional biopsy (1)

1. used on limited to small superficial lesions

where do we apply FISH? (3)

1. viral infections e.g., HPV, EBV, HIV, CMV, HCV etc. 2. tumors for detection of gene expression and oncogenes (burkitt lymphoma t8:14) 3. chromosomal disorders

what types of tissue samples can we gather? (2)

1. wax tissue sample: tissue fixated in formalin 10% to keep normal cells. we use 10x the volume of the tissue. formaldehyde + water 1:10 (10%) 2. frozen section

ATPase stain

ATP type 1 and 3 fibers- dark/pale

how do we prepare celloidin embedding?

Celloidin embedding by use of alcohol solution. processed by room temp. no shrinkage and minimal distortion of tissue, gives hard blocks which gives better support to tender tissues. but it is slow, problematic sectioning and thick sections

feulgen reaction stain

DNA-red purple

kind of needle biopsy we have

FNA (fine-needle aspiration biopsy)

the ultimate goal of pathology

ID of the cause of disease that leads to a successful therapy and prevention of disease

What is the difference between how pathologist studied the human previously and now?

Previously: studying healthy human construction of the body (anatomy), tissue (histology), and cell (cytology). their function based on biology, biochemistry, physiology. Now: studying diseased humans, the structure of the function. nature of disease, concering the changes of human organism caused by disease.

what do we examine from a biopsy?

a sample of tissue from a living body which is taken from the body in order to examine it more closly

definition: health

accoding to WHO, state of full physical, mental and social happiness. it depends on the ability to adapt to the environment

Ziehl-Neelsen stain

acid fast bacteria- red

acid phosphatase stain

activity- black

alkaline phosphatase stain

activity- brown/black

what is transplantation immunity?

auto, -iso-, allogenic, xeno etc

Bielschowskys silver stain

axons and neurofibrils- black

why don't we need to do autopsies so often anymore?

better techniques, good diagnostic, technical abilities to check if process was done correctly or not- autopsies are now done only in those cases where there are problems, to check diagnostic and therapeutic process

hypostasis changes of postmortem

blood accumulation at the base of visceral organs

lugouls solution

blue amyloid

toluidine blue

blue amyloid/cytoplasmic granules of mast cells (heparin)- dark blue

definition biological death

brain death or cell death, cessation of electrical activity in the brain- irreversible

alaline blue

carbohydrates blue

what is clinical/surgical pathology

cause of disease and symptoms. examination of living person. example: small surgeries, endoscopy etc. biopsy and cytology. diagnostic of disease by macro/microscopic analysis of the cells and tissues. different types of biopsies: exicion, inscisional, core needle, fine needle aspiration. this forms the bulk of tissue material for the pathologist and includes study of tissue by paraffin embedding techniques and by frozen section for rapid diagnosis, in contrast to autopsy (examination of dead person)

what does study of cellular adaptation look at?

cellular adaptation to injury, necrosis (death of living cells or tissues), inflammation, wound healing, and neoplasia (abnormal new growth of cells), which in turn give rise to the presenting signs and symptoms of the patient

masson's trichrome stain

collagen- blue nuclei- black/blue smooth muscle- red

Van gieson's stain

collagen- red nuclei- black, blue

definition of clinical manifestations

consequences of changes

what is flow cytometry used for?

count and analyse the size, shape and properties of cells. determination of the immunophenotype of cells. useful for different types of leukemia and lymphoma, also diagnosis of autoantibodies, measure of nucleic content, proliferation-associated antigen e.g. Ki67, PCNA

ultimate criteria of death

death of the brain, meaning no brain activity.

what is pathological physiology?

describes functional changes due to disease. pathophysiology comprised by 2 words: patho= suffering, physiology= study of normal function

what is pathological anatomy?

describes morphological changes due to the disease. deals with etiology of disease, these being 1) non-living agents, 2) living agents (bacteria, virus), 3) trauma, 4) chemical

what is molecular physiology?

detection and diagnosis of abnormalities at the level of DNA of the cell

what is frozen section biopsy?

diagnostic procedure done before surgery, where the tissue is fresh and not stained

what are pathologists?

diagnosticians of disease

definition: illness

disease suggests an entity with a cause, illness is the reaction of the individual to disease in the form of symptoms (complaints of the patient) and physical signs (elicited by the clinician). though disease and illness are not separable, the study of disease is done in pathology while the learning and management of illness is done in wards and clinics.

what type of process is disease?

dynamic process, not static, disease has end, treatment will be successful or not

orecein stain

elastic fibers- reddish brown

exicion biosy:

entire lesion removed

what dyes do we use to color something acidophilic?

eosin, orang G, fuschin

what are the indications for frozen section of soft tissue lesions?

establish if lesion and/or viable tissue is present, evaluate margings, definitive diagnosis prior to surgery. is is a definitive diagnosis prior to surgery. it is a rapid intraoperative diagnostic procedure for tissues before proceeding to a major radical surgery. besides, it is also used for demonstration of certain constituents which are normally lost in processing in alcohol e.g., fat, enzymes

what does a forensic pathologist do?

examine the patient post mortem (autopsy) after a crime incident, murder, car accidents.

What does a pathologist do?

examine the patient when admitted to the hospital, and dies. Also biopsies from living patients and dead to ensure right and propper treatment was given

what do we use to stain proteins and nucleic acid with: 1

feulgen reaction

PTAH stain

firbin, looks like trichrome

what does pathology embrace?

functional and structural changes in disease, from the molecular level to the effects on the individual

grocott's stain

fungi- black

PAS stains

glycogen/mucin- red violet

gram's stain

gram positive= blue gram negative= red

what is flow cytometry?

has a laser-light source for fluorescence cell transportation system in a single stream

what dyes do we use to color something basophilic?

hematoxylin, toludin blue, methylene blue

PEARLS stain

hemosiderin-blue

definition histochemical analysis

histo= tissue, chemical=chemical procedures, together: chemical reactions in the tissue, with expected result of being able to demonstrate the presence of the given chemical substance. microscopic examination of stained tissue. samples from biopsies (living tissues), autopsy (necropsy/dead tissue), or cytology. examples of enzymes: mucin, glycogen. stains. PAS, congo red, HE, chloroacetate esterase (enzyme present in cytoplasm of mast cells in skin, this is the mastocytosis in the skin and to prove this is really mast cells, apply stain and prove the diagnosis)

definition pathogenesis

how disease has been born, development of the disease and how. how etiological factors trigger cellular and molecular changes that gives rise to the specific functional and strucutral abnormalities that characterize the disease. fromal pathogenesis: HOW, a complex of all the factors responsible for the onset and development of the disease from start to final stages. causual pathogenesis (WHY) a complex of all the changes and reactions, which occur in the organism during the disease course= causes of the manifested morphological chanegs

what is immuno pathology?

immunodeficiency where they look at congenital vs aquired immuonodeficiencies. the immunoproliferative states: monoclonal vs polyclonal. autoimmune disorders, hypersensitivity disorders types 1-4

what is cytogenetics:

karyotyping: chromosomal alignment on the basis of size, centromeric location and baning pattern. use cells capable of growth, then put them in a culture with mitogen substance that induces mitosis. then arrest them in metaphase and fix and stain them. giemsa staining is most commonly used. we can see p or q arm under the microscope.

what is FISH (fluroscent in situ hybridization)?

localization of nucleic acid sequence directly in the intact cell (i.e. in situe) without DNA extraction. it involves specific hybridization of a single strand of a labelled nucleic acid probe to a single strand of complementary target DNA or RNA in the tissue. the end-product of hybridisation is visualised by radioactive labelled probe (32P, 125I), or non-radioactive-labelled probe (e.g., biotin, digoxigenin). need a probe that is a complementary sequence that are labelled, detected by enzyme linked antibody or fluroscently linked antibody system

what is general pathology?

looking at organisms of different structure, architecture, metabolism etc and how they show similar structural changes. cellular and tissue alterations caused by pathologic stimuli in most tissues. this provides the basis for understanding the fundamentals of the disease process. these are transient or permanent increase= anabolism= progressive or decrease= catabolism of metabolism, or general dysfunctions= dystrophies= regressive changes

definition of clinical death

loss of vital functions- heart and lung- reversible, most organs are still alive (kidneys, eyes) and can be used for transplantation

postmortem changes: diffusion of fluid

maceration (softening and soaking of tissue as if it had been in water) of tissue (fluid from vessels through the body), desquaation of skin (shedding of the outer layers of the skin)

definition: syndromes

meaning running together, characterised by combination of symptoms caused by altered physiologic processes

definition morbid anatomy

means autopsies. learning from the dead orientated on the living persons (patients)

the different types of cutting of specimens

micritome- for ligh microscopy, steel blades (1-10 micrometer thick) using microtome. electron microscopy- glass or diamond blades freezing microtome (crystat)- specimen freezed in liquid nitrogen. quick (perioperative biopsy), save lipids. sections are given to the slides (light microscope) or metal grids (electron microscope). frozen tissue embedding in a freezing medium is cut on a microtome in a cooled machine called a cryostat

What is PCR (polymerase chain reaction)?

molecular method technique for molecular genetic purpose with widespread applications in diagnostics and research. in PCR, a single strand of DNA generates another by DNA polymerase using a short complementary DNA fragment; this is done using a primer which acts as an initiating template

What is pathognomic?

morphological or functional changes which is typical for a given disease. like some symptoms are typical for the disease, while others are not typical for it.

luxol fast blue stain

myelin- blue/green cells- violet/pink

3 main techniques in pathology:

necropsy, biopsy, cytology

definition autopsy

necropsy/autopsy= examination of dead person. evaluation of the autopsy is macroscopic and histological evaluation, in autopsy, pathologist has sample of organs, tissues and so on, and examine in the microscope. autopsy biopsy (and cytology). morbid pathology but not forensic pathology. can be complete (multiple organs involved) or mini-autopsy (organ specific disease). clinical pathology is a living person in contrast

types of biopsy:

needle, incisional, excisional,smear and sputum(cytologic).

what cannot ICH stains be applied to distinguish between?

neoplastic and non-neoplastic lesions, or between benign and malignant tumors. these distinctions have to be done by traditional methods in surgical pathology

What is a core needle biopsy?

not only cells, but surrounding tissue is sampled

core needle

not only cells, but surrounding tissue, used in breast biopsy

what does H&E stain?

nucleus, bacteria, calcium H-blue cytoplasm, connective tissue and all other tissues E-red: most commonly used stain

oil red stain

oils-red PL+ unsaturated fat- pink

what is cytologic examination?

only cells are examined, like a pap smear which is common cytologic evaulation

definition etiology

origin of disease, including the underlying causes and modifying factors. it is important to understand the genetic and environmenatl factors which can be external: comin from outside the organisms (living-microbes/non-living agents like physical and chemical) and internal: genetical background, mutations of genes, chromosomes. patients can be predisposed or are resistant to certain conditions while others are very sensitive to different conditions. it can also be familiary/inherited (DM, Ca mammae etc) its also genetical but patient will be born with it

giemsa stain

parasites, protozoa- dark blue blood: RBC= red, WBC=blue

what is systemic pathology?

pathology of different specialized organs

what is oncopathology?

pathology of tumor's disease

Definition of pathology:

pathos= suffering logos= study Pathology= study/science of disease in general, abnormalities that occur in normal anatomy (including histology) and physiology owning to disease

Catergories of early postmortem changes

physical and chemical

postmortem changes: diffusion of gas

pseudomelanosis of abdominal organs. EX: from intestines through the whole body. brown pigment, lipofuscin in macrophages, not melanin. EX: H2S leads to changed Hb into verdoglobin that leads to pseudomelanosis= stains the tissues with pigment

Congo red:

red amyloid

what is immunopathology of neoplasia?

relations to immunotherapy of neoplastic disorders as well as others like hematology, chemical pathology (e.g. analysis of biochemical constituents of blood, urine, semen, CSF and other body fluids), and medical genetics (very important field)

how to interpretation of results of IHC stains

remember that different antigens are localised at different sites in cells (membrane, cytoplasm or nucleus) and accordingly positive staining is seen and interpreted at those sites e.g. membranous staining for leucocytes common antigen (LCA), nuclear staining for estrogen-progesterone receptors (ERPR), cytoplasmic staining for smooth muscle actin (SMA) etc.

fine needle aspiration

removal of cells, for palpable mass in for example thyroid

what is decalcification of biopsy mean?

removing calcium from tissues, like bone, bone marrow, teeth, by aggressive acids (EDTA)

what is the latest research on their department concerning parafin block techniques:

research on GIST's and C-kit. Some tissues need EM like minimal changes GN. FISH+IHV with ER/PR(good sign if present) and HER2 (bad sign if present, but more available target therapy) for breast ca.

gomori stain

reticular fibers- black

inscisional biosy

small area of tissue is taken

what is incisional biopsy?

small area of tissue is taken

what is embedding?

soft, moist tissue are turned into a hard paraffin block, which is then placed in a mold containing more molten wax and allowed to cool and harden. it enables specimen to be cut.

what is mounting of specimen?

spread the section on slide (with/without fixative- mayers salbumen, haupts gelatin) after staining, cover the slide by cover glass (by canadian balsam) or solacryl (polymer)

what is staining?

staining gives the tissue colors, because tissues are colorless. dying methods: diffuse/selective orthocrhomatic/metachromatic. dyes: basic (hematoxylin, toludin blue, methylene blue), color the basophilic components. acid (eosin, orang G, fuschin) color the acidophilic component

definition: disease

state which does not correspond to the conditions of health- when a moment of adaptability is overrun, disturbed= disease= the change which the organism can not compensate (run: tachycardia physiological vs pathologic)

IH stain

striated muscle + mitochondria- black

definition of morphological changes

structural alterations of cells

what is ultrastructural (electron-microscopical analysis)?

structural and function of normal and diseased cells at level of cell organelles. not used a lot, but technique can be used for diagnosis of kidney disease. for organelles, nuclei, nucleoli, ribosomes, ER, mitochondria etc.

What type of medical science is pathology?

study and diagnosis of disease through the examination of surgically removed organs, tissues (biopsy samples), cells, bodily fluids, and in some cases the whole body (autopsy)

define pathology:

study of disease, etiology of disease and pathogenesis of disease

what is an excisional biopsy

the entire lesion is removed

definition of death

the moment when all our physiological functions are gone. death is defined as an irreversible ceassation of all functions of the entire brain, including the brain stem. loss of cognitive function, as evidence by the death of the cerebral cortex

what is the science of pathology?

the situation of a disease both natural and morphological changes

what do we use genetic methods/molecular pathology/tissue cytogenetics for?

they have genes as reseptors for the signaling pathway. gives us visualization of chromosomes to identify genetic defects such as chromosomal translocation. today: DNA, mRNA and genes are surviving the fixation. commerce production of the probes and other assays usable also on formalin-fixed paraffin-embedded

sudan black stains

unsaturated fat- blue/black

osmium tetraozide stains

unsaturated lipids- brown/black saturated lipids- unstained

how to we prepare plastic embedding?

used for electron microscopy or IHC. Resin at room temp polymerize into hard polymer. gives hard blocks which gives better support to tender tissue and very thin sections with good details but it is expensive and dangerous (cardinogenic resins ) gelatin++ check

what is fine needle aspiration biopsy?

used for palpable masses

what is histopathology?

used synonymus to pathoanatomy, macro/microscopical changes. under here is surgical pathology, forensic/autopsy and cytopathology (includes study of cells shed off from the lesions (exfoliative cytology) and FNAC (fine-needle aspiration cytology)

definition immunohistochemical analysis

using antibodies to demonstrate presence or absence of given antigen and its presence or absence is visualized by the chemical analysis. part of cellular pathology. technique used to detect status and localisation of particular antigen in cells (membrane, cytoplasm or nucleus) by use of specific antibodies which are then visualised by chromogen as brown color. helps determining cell lineage specifically, or used to confirm a specific infection. the need for fluorescent microscope was obviated (avviklet) by subsequent development of horseradish peroxidase enzymatic labelling technique with some colorgenic system instead of fluorochrome so that the frozen section with labelled antibody could be visualised by light microscope

how do we embed frozen sections?

using frozen, non-fixed tissue in a freezing medium, which is liquid in room temp but when cooled will solidify. non-fixed tissue allows for procedures such as in situ hybridizations for specific mRNAs that would have been destroyed during fixing process

macroscopic and microscopic

view of tissue/organs

how do we prepare wax embedding?

wax-embedding is most common. use melted peraffin (50-60C). it is universal, simple, cheap, quick, gives thin sections, and serial sections.

definition of somatic death

whole body and necrosis, death of tissue and organs. autolysis= cell death in dead person