CELL TYPE SELECTION
         The cell type chosen will depend on the question being asked.
              DNA synthesis, 
              Response to cytotoxins, 
              Apoptosis, 
              Monitoring the production of factors, proteins, enzymes,
              Toxicity testing or pharmacuetical  assays to evaluate effects on organelles
         Cell line selection begins with the first step as literature survey
              to determine from the literature whether a cell line exists with the required 
               properties.
              The cell line to be studied and its possible controls as cell are available or not
              The research or study plan specifics and assay condition compatibility with cell 
               and its supplements
         The cell types may not matter provided the cells are competent and assay 
          conditions to perform a research activity is compatible with culturing 
          conditions or can be controlled easily. 
      CELL TYPE SELECTION
         Normal and healthy cells or tumorigenic cells are the main objective to 
          perform a TCC task
              Normal tissue cells have finite lifespan, while cultures from tumours give rise to 
               continuous cell lines. 
              However, there are several
         examples of continuous cell lines derived from normal tissues and which are 
          non-tumorigenic. 
         Some representative cells of this type are:
              BHK-21 hamster kidney fibroblasts, 
              MDCK dog kidney epithelium, 
              3T3 fibroblasts.
   Culture selection based on culturing and maintenance conditions
        adeherent cell cultures 
            Cultures are propagated as a monolayer attached to the substrate are 
             called adeherent cell cultures which may not need centrifugational 
             procedure while analyzing the culture media, or harvesting cells for 
             microscopic examinations, etc. 
            Adherent cells are easy to handle interms of assay conditions but hard to 
             passage, count and revive comparing the procedures with that of 
             suspension cells.
        Suspension culture 
            Some of the adherent cells or transformed cells, haematopoietic cells, and 
             cells from ascites can be propagated in suspension. 
            Suspension  culture  has  advantages,  including  simpler  propagation 
             (subculture  only  requires  dilution,  no  trypsinization),  no  requirement  for 
             increasing surface area with increasing bulk, ease of harvesting,and the 
             possibility of achieving a 'steady state' or biostat culture if required
  Common Cell lines are used in TCC-1
  Common Cell lines are used in TCC-2