space.template.CELL+CULTURE

All living things are made up of cells. There are many principal methods and techniques used to study cells and their components. With the appropriate surroundings, most cells can live, multiply and even express differentiated properties in a tissue-cultured dish (figure 1). The cells can be watched under a microscope or analyzed biochemically. Experiments that are performed without organisms (on cultured cells) are said to be "in vitro" (meaning "in glass") while the contrast is referred to as "in vivo" (meaning "in living organism") (Davis, 2011).
 * CELL CULTURE **

 Figure 1. Cell culture in petri dish

Cell culture is the growing of animal or plant cells in a favorable artificial environment. The cells may be removed from the tissue directly and disaggregated by enzymatic or mechanical means before cultivation, or they may be derived from a cell line or cell strain that has already been already established (Life technology).
 * WHAT IS CELL CULTURE? **

The main objective of cell culture is to isolate parts from the whole organism for study in experimentally controlled environments. Isolating cells and growing them in culture provides a much more detailed biochemical analysis. Tissues can be purified and used for biochemical analysis or for the establishment of cell cultures (Alberts et al., 2008).
 * Purpose **


 * Types of cell culture **

//1) Primary Culture // Primary culture refers to the stage of the culture after the cells are isolated from the tissue and proliferated under the appropriate conditions until they occupy all of the available substrate (i.e., reach confluence). At this stage, the cells have to be subcultured (i.e., passaged) by transferring them to a new vessel with fresh growth medium to provide more room for continued growth (Life technology).

//2) Cell Line Culture // <span style="font-family: 'Times New Roman',Times,serif;">After the first subculture, the primary culture becomes known as a cell line or subclone. <span style="font-family: 'Times New Roman',Times,serif;">Cell lines derived from primary cultures have a limited life span (i.e., they are finite; see <span style="font-family: 'Times New Roman',Times,serif;">below), and as they are passaged, cells with the highest growth capacity predominate, <span style="font-family: 'Times New Roman',Times,serif;">resulting in a degree of genotypic and phenotypic uniformity in the population (Life technology).

<span style="font-family: 'Times New Roman',Times,serif;"> a) Cell Strain <span style="font-family: 'Times New Roman',Times,serif;"> If a subpopulation of a cell line is positively selected from the culture by cloning or some <span style="font-family: 'Times New Roman',Times,serif;"> other method, this cell line becomes a cell strain. A cell strain often acquires additional <span style="font-family: 'Times New Roman',Times,serif;">genetic changes subsequent to the initiation of the parent line (Life technology)


 * <span style="font-family: 'Times New Roman',Times,serif;">BASIC EQUIPMENT **

Even though specific requirements of a cell culture lab depends on the type of study being conducted, all cell culture labs have the common requirements of being free from pathogenic microorganisms. In addition, the basic equipments are the same. <span style="font-family: 'Times New Roman',Times,serif; line-height: 0px; overflow: hidden;"> Figure 2. The basic layout of a cell culture hood for right-handed workers. The layout is reversed for left-handed workers.

media type="file" key="Introduction to Cell Culture - Gibco® Cell Culture Basics.mp4" width="300" height="300" <span style="font-family: 'Times New Roman',Times,serif;">Cells in culture can be divided in to three basic categories based on their shape and appearance (Figure 2). Fibroblastic cells are not only bipolar and multipolar but also grow attached to a substrate. Unlike Fibroblastic cells, Epithelial-like cells are polygonal with more dimensions. They also grow attached to a substrate but in discrete patches. Lastly, lymphoblast-like cells are spherical in shape and are usually grownin suspension without attaching to the surface (Life technologies)
 * TECHNIQUES**
 * <span style="font-family: 'Times New Roman',Times,serif;">MORPHOLOGY OF CELLS IN CULTURE **

<span style="font-family: 'Times New Roman',Times,serif;"> <span style="font-family: 'Times New Roman',Times,serif;">Figure 2. The three groups in which cells in a culture are classified are A) Fibroblastic cells B) Epithelial-like C) Lymphoblast-like (Life technologies, year).

<span style="font-family: 'Times New Roman',Times,serif;"> History/origin <span style="font-family: 'Times New Roman',Times,serif;"> Cell culture dates back to the early twentieth century. In 1907, Ross Harrison published experiments showing frog embryo nerve fibre growth in vitro. In 1912, Alexis Carrel cultured connective tissue cells for extended periods and showed heart muscle tissue contractility over two to three months. In addition, it was shown in 1949 that poliovirus could be grown in cultures of human cells, and this became one of the first commercial "large scale" vaccine products of cultured mammalian cells. By the 1970s, methods were being developed for the growth of specialized cell types. Today, cultures are more commonly made from suspensions of cells dissociated from tissues (Alberts et al., 2008).

<span style="font-family: 'Times New Roman',Times,serif;">recent research

<span style="font-family: 'Times New Roman',Times,serif;"> Li et al. (2012) utilized cell culture to grow bone marrow cells that were removed from mice. In addition, dendritic cells treated with Interleukin-12 shRNA were co-cultured. This technique is important to the final analysis of the paper because it offers the ability to generate vaccines not only for stimulation but also for inhibition. this technique revealed that although in vitro transfection efficacy may be high and can be expressed in a stable manner, in vivo use may be more practical and safer (Li et al., 2012).

<span style="font-family: 'Times New Roman',Times,serif;">Li et al. (2010) transferred cloned prions from brain to cultured cells which was essential in determining that the “cell-adapted” prions outcompeted their “brain-adapted” counterparts. This technique was necessary for the transfer of the prions to and from the brain. The technique revealed that the opposite occurred when prions were returned from cells to brain (Li et al., 2010).

<span style="font-family: 'Times New Roman',Times,serif;">Harkness et al. (2012) utilized this technique by a method of stable isotope labeling with amino acids during cell culture (SILAC). The technique was important because it allowed for the identification of cell signaling pathways as well as the analysis of differential expression of protein (Harkness et al. (2012)

//**<span style="font-family: 'Times New Roman',Times,serif;"> References **//

<span style="font-family: 'Times New Roman',Times,serif;">Alberts, B., Johnson, A., Lewis, J., Raff, M., Roberts, K., & Walter, P. (2008). Molecular Biology of The Cell Fifth Edition. New York: Garland Science, Taylor & Francis Group.

<span style="font-family: 'Times New Roman',Times,serif;">Davis, J. M. (2011). Animal Cell Culture: Essential Methods (pp. 34-36). Hoboken, NJ: Wiley; 1 edition.

<span style="font-family: 'Times New Roman',Times,serif;">Li et al. (2012) utilized cell culture to grow bone marrow cells that were removed from mice. In addition, dendritic cells treated with Interleukin-12 shRNA were co-cultured. This technique is important to the final analysis of the paper because it offers the ability to generate vaccines not only for stimulation but also for inhibition. this technique revealed that although in vitro transfection efficacy may be high and can be expressed in a stable manner, in vivo use may be more practical and safer (Li et al., 2012).

<span style="font-family: 'Times New Roman',Times,serif;">Li et al. (2010) transferred cloned prions from brain to cultured cells which was essential in determining that the “cell-adapted” prions outcompeted their “brain-adapted” counterparts. This technique was necessary for the transfer of the prions to and from the brain. The technique revealed that the opposite occurred when prions were returned from cells to brain (Li et al., 2010).

<span style="font-family: 'Times New Roman',Times,serif;">Harkness et al. (2012) utilized this technique by a method of stable isotope labeling with amino acids during cell culture (SILAC). The technique was important because it allowed for the identification of cell signaling pathways as well as the analysis of differential expression of protein (Harkness et al. (2012)

<span style="font-family: 'Times New Roman',Times,serif;">Life technology, [|www.invitrogen.com/cellculturebasics].

http://www.youtube.com/watch?v=ZBDSok3SMRY