Tissue Culture and Aseptic Techniques

Tissue Culture

• A laboratory technique for growing cells, organs, or tissues in a controlled environment.
• Grown under specific conditions including sterility, light, pH, temperature, nutrients, humidity.
• Requires a nutrient-rich medium tailored to the specific needs of the tissue, cell, or organ being grown.

Culture

• The process of growing microorganisms, tissues, cells, or organs on a growth medium.
• The type of growth medium depends on the experiment's objective.
• Liquid media is used for isolating or extracting DNA from bacterial cells.
• Solid media is used for growing bacterial colonies.

Contaminant

• Any unwanted substance or microorganism that hinders the growth of the desired culture.

Aseptic Techniques

• Procedures designed to prevent contamination of a culture.
• Examples include laminar flow hoods, biosafety cabinets, and ethanol solutions.

Callus

• A mass of undifferentiated cells that can proliferate.
• It is a key component of tissue culture and can be induced to differentiate into different types of plant tissues.

Micropropagation

• Producing a large number of plants from a small piece of plant material in a short period of time.
• Requires less space than traditional methods of plant propagation.
• Example of aseptic techniques used in plant biotechnology.

Pathogen

• A disease-causing organism.

Pathogenic

• Capable of causing disease.

Sterile

• A culture free of viable microorganisms.

Sterile Techniques

• Procedures used to make something sterile.

Clone

• A plant that is produced asexually from a single parent plant.
• All clones are genetically identical to the parent plant.

Clonal Propagation

• Asexual reproduction of plants, producing genetically identical offspring.

Explant

• A piece of tissue, cell, or organ excised from a plant and transferred to a growth medium to be cultivated in vitro.

In Vitro

• Growth of an organism in a controlled artificial environment, such as a test tube or petri dish.

In Vivo

• Growth of an organism in its natural habitat, such as a field.

Regeneration

• The ability of an organism to restore or replace damaged cells or tissues.
• Natural Regeneration: The process occurs naturally without any external intervention.
• Artificial Regeneration: Guided regeneration of cells or tissues in a laboratory environment.

Growth Regulators

• Hormones that help to regulate plant growth and development.
• Used in tissue culture to induce cell division, differentiation, and regeneration.

Somaclonal Variation

• Unintentional variations that occur in plants during tissue culture.
• These variations are often observed in the phenotype.
• The exact cause of somaclonal variation remains unknown.

Somaclones

• Plants with somaclonal variation.

Recalcitrant

• An explant that is difficult to culture, resists growth despite optimized conditions.

Subculture

• Transfer of a culture from one growth medium to another.
• Used to refresh the medium, remove toxic metabolites, and promote the growth of specific tissues.

Totipotency

• The ability of a cell to give rise to all other cell types, ultimately developing into an entire organism.
• Cells retain the potential to differentiate into any cell type.

Ploidy

• The number of sets of chromosomes a plant possesses.
• Different ploidy levels can affect plant traits, like appearance and nutritional value.

Shoot Apical Meristem

• Located at the tip of the shoot, it is an area of actively dividing cells that produce leaves, buds, and stems.

Meristem

• A region of actively dividing cells in plants.

Apical Meristem

• Located at the tips of roots and shoots, and at the origin of lateral branches.

Meristematic

• Having the characteristics of a meristem, capable of growing.
• Meristematic cells have high mitotic activity.

Meristemoid

• A localized group of meristematic cells that arise in callus and give rise to roots or shoots.

Undifferentiated

• Cells that do not have a specialized or mature structure or function.

Dedifferentiation

• Artificial process in tissue culture.
• Specialized cells revert to an undifferentiated state.

Redifferentiation

• Shifting a dedifferentiated callus into a new differentiated cell type.

Differentiation

• The process of unspecialized cells becoming specialized for different functions.
• An essential part of plant development and growth.