metode de cercetare eng

Methods used inCytology, Embryology and

HistologyStudy of live tissueStudy of dead tissue (fixated)

CytologyFormulation of the cell theory

In vivo study of live tissue

In vitro study of live tissue

Vital and extravital staining of tissue

The study of dead (fixated) cells and tissue

Types of histological slides1) Smear2) Film3) Print4) Histologic section

Steps of tissue preparations•Acquisition of biological sample and fixation•Embedding•Cutting of sections•Staining•Mounting

Light microscopy

Phase contrast microscopy

Polarizingmicroscopy

UV microscopy

Fluorescent microscopy

Autoradiography Historadiography

Cyto- and histochemical methods

Immunohistochemistry

Electron microscopyTransmission EM

Transmission EM

Scanning EM

Scanning EM

Cell theory – classical formulation(Mathias Schleiden şi Theodor Schwann [1839])

1. All organisms are made up of one or more cells

2. The cell retains a dual existence as a distinct entity and a building block in the construction of organisms

3. All cells come from preexisting cells [omnis cellula e cellula] (Rudolph Virchow)

4. All cells of an animal or vegetal body come from the fertilized egg (Karl Baer)

Cell theory – modern interpretation1. The cell is the fundamental unit of structure and

function in all living things2. All cells are basically the same in chemical composition

3. All cells come from preexisting cells by division

4. Cells contain hereditary information (DNA) which is passed from cell to cell during cellular division

5. All known living things are made up of cells

6. The activity of an organism depends on the total activity of independent cells