Cytology, General Histology and Embryology - V. K. Naphanyuk 2002

Methods of Histological Research
Vital Staining Methods
Study of Living Structures in Cell and Tissue Culture

Methods FOR STUDYING living structures in Cell and tissue cultures (in vitro) are currently the most widespread.

The Essence of these methods is that Cells, small tissue samples, or Organs isolated from human or animal organisms are placed in sterile plastic or Glass vessels containing special nutrients (Blood Plasma, embryonic extract) and cell growth stimulators. Complete sterility of the environment and a body-matching Temperature are maintained throughout the process. Under these conditions, cells retain their main vital Functions for a long time (ability to grow, reproduce, differentiate, and move). These cultures can survive for many days, months, or even years, provided the growth medium is periodically renewed and the cells are subcultured into fresh vessels.

Suspension cultures (cells suspended in the growth medium) and monolayer cultures (cloned cells forming a continuous layer on glass) are distinguished.

The cultivation method has helped reveal certain regularities in cellular differentiation, malignant transformation, cell-to-cell interactions, and the interactions of cells with Viruses and microbes. Culturing embryonic Tissues has made it possible to trace the Development of Bones, Skin, and other organs. This method has demonstrated the ability of Cartilage cells to form intercellular substance in culture, and Adrenal gland cells to synthesize Hormones.

This method is of particular importance when conducting experimental research on human Cells and Tissues. Cells obtained from The Human Body via biopsy or puncture can be used in tissue culture to determine sex, Hereditary diseases, and malignant transformation.

Cell Hybridization Method

The essence of this method is that cell hybrids can be obtained from cells of any type and developmental stage by treating them with various factors (inactivated parainfluenza virus, polyethylene glycol, etc.). As a result of such Treatment, heterokaryons containing Two Types of genotypes are formed within the resulting hybrids. Studying the protein products of Gene activity makes it possible to map the localization of genes within the chromosome. This approach forms the basis for producing Monoclonal Antibodies, which allow researchers to identify various Developmental Stages of immunocompetent and other cells.

Despite their great Prospects for application, these methods have very significant drawbacks. The most critical limitation of studying living cells, tissues, and organs in vitro is that isolating cells from the intact Organism alters their living conditions: interconnections with other cells and tissues are lost, and METABOLISM/18.html">The Influence of neurohumoral regulatory factors is excluded.

Method of Cell and Tissue Cultivation In Vivo

This method of investigating living cells and tissues makes it possible to overcome the aforementioned limitations of in vitro cultivation.

The essence of this method is that samples of cells, tissues, and organs are placed in chambers made of a porous material, which are subsequently implanted into an animal's body (into the Abdominal cavity, subcutaneously, etc.).

Staining Methods

The vital staining method involves coloring cells and tissues by introducing a dye into a living animal's body, which selectively stains specific cells, their Organelles, or the intercellular substance.

Examples of such Dyes include trypan blue or lithium carmine (which stain phagocytes) and alizarin (which stains the bone matrix).

The supravital staining method involves staining living cells that have been isolated from the organism. This method is used to detect young forms of erythrocytes—blood reticulocytes (using brilliant cresyl blue), Mitochondria in cells (using Janus green), and Lysosomes (using neutral red).