General overview of cell culture

INTRODUCTION: Cell culture refers to the removal of cells from eukaryotic or prokaryotic organisms and grown in a controlled environment. They are grown in controlled conditions to make a cell line which has important applications. The cells can be extracted directly from the tissue and disaggregated by enzymatic or mechanical methods before culture, or they can be generated from an existing cell line or cell strain.

Although there are significant variations, mammalian/animal cell culture procedures are fundamentally comparable to those used for bacteria, fungus, and yeast.

HISTORY:

1907: 1^st successful tissue culture was made in vitro by the hanging drop technique by Ross Granville

1911: Alexis Carrel and Montrose Burrows defined the term tissue culture and established the first cell line using diluted blood plasma for the media

1920: cell culture formulations were made using compositions of salt solutions

1940: antibiotics were used in cell culture

1960: manufacturing of carbon dioxide incubators

APPLICATIONS OF CELL CULTURE:

Cell culture technology plays a significant role in the following areas:

• RESEARCH STUDIES:  Basic cell biology, interactions between disease-causing substances and cells, medication effects on cells, ageing processes and triggers, and nutritional studies are all being researched.

 

• DEVELOPMENT OF ARTIFICIAL TISSUES

 

• DEVELOPMENT OF BIOLOGICAL COMPOUNDS

 

• TOXICOLOGY TESTING: Investigate the impact of new medicines

• CARCINOGENESIS AND MUTAGENESIS: research investigate the role of different substances, viruses, and radiation in the conversion into cancerous cells from normal cells and study of mutations within the cells and their causes.

 

• DRUG DEVELOPMENT AND SCREENING: it is used to manufacture and study the effect of drugs

 

• VIRAL RESEARCH AND VACCINE DEVELOPMENT: Cultivation of viruses for vaccine development, their structure with research into their infectious cycle and diseases

 

• GENETIC ENGINEERING: is used in the creation of commercial proteins as well as the large-scale generation of viruses for use in vaccine manufacturing, such as polio, rabies, chicken pox, hepatitis B, and measles

 

• TOOL IN CELLULAR AND MOLECULAR BIOLOGY: major tool and model system used to observe the effects and study the normal physiology and biochemistry of cells

 

• GENE THERAPY: is a type of therapy in which genes are used to cure cells with a functioning gene can be replaced by cells with a non-functional gene. 
  

 

TISSUE CULTURE: in vitro cultivation of cells, tissues and organs in controlled temperature and nutrient and growth factor id known as tissue culture

PRIMARY CULTURE: First a suitable tissue is extracted depending in our studies or target from the organisms either through surgically or enzymatically and is grown under optimum conditions. These cells are known as primary cells. They have a finite life span of heterogeneous cells closely having the morphological structure as in vivo and are more genetically stable. Following are the techniques for developing primary culture:

• MECHANICAL DISAGGREGATION: it is done by sieving, syringing and pipetting. it is inexpensive and only done when the viability of cells is not important

 

• ENZYMATIC DISAGGREGATION: the disaggregation of cells is done in high yield by using enzymes such as trypsin, collagenase, collagenase + hyaluronidase, etc.

 

• PRIMARY EXPLANT TECHNIQUE: tissue is kept in basal salt solution and chopped finely after washing is uniformly distributed over growth surface. After addition of medium it is incubated for 3-5 days. 
  

 

SECONDARY CULTURE: when the cells reach the stage of confluence, they are subculture or passage into a new fresh medium to provide optimum growth conditions. After the first sub culture the primary culture becomes known as a cell line. They have the highest growth capacity resulting in homogenous cells with a bit genetically unstable. They are finite but with subsequent sub culturing mutations may arise and turn them into a continuous culture with unlimited life span if provided with optimum conditions

CELL CULTURING:  cells are cultured by adherent culture or suspension culture. Adherent cultures are monolayer on an artificial substrate. Cells mostly isolated from vertebrates are anchorage dependent besides hematopoietic and others. They need to be cultured on a suitable substrate which allows cell adhesion and spreading.

In suspension culture cells are free floating in the medium. They are not anchorage dependent e.g. hematopoietic stem cells etc . . . . they are easier to passage and don’t require enzymatic or cellular dissociation.

LIMITATIONS OF CELL CULTURE:

• It require expertise in sterile handling and effective maintenance of cells or the cultured might get contaminated through chemical or microbial source
• Its requires a lot of scale up , equipment, quantity and is costly to maintain
• Maintaining the environment for sterile aseptic conditions is very difficult
• Due to rapid growth rate mutation and genetic instability is a high risk
• Identification of cell type is difficult without standardization as markers are not always expressed

 

REFERENCES:

1. Abbott, Alison. "Cell culture: Biology's new dimension." Nature, vol. 424, no. 6951, 21 Aug. 2003, pp. 870+. Gale Academic OneFile, link.gale.com/apps/doc/A187749303/AONE?u=anon~a1289cf0&sid=googleScholar&xid=df42b3c3. Accessed 4 Sept. 2021.
   
2.  Overview of Cell and Tissue Culture Techniques’’ Paul Honegger  First published: 15 May 2001 https://doi.org/10.1002/0471141755.ph1201s04

 

 By: Marium Imran