**2.1. Two-dimensional (2D) cell culture system**

Two-dimensional culture conditions vary widely for each cell type. Appropriate cell culture medium suitable for the growth of particular cells has to be used. Various laboratories use different recipes of cell culture media prepared in the laboratory or commercially produced. The commercially produced cell culture medium is obtained sterile and ready to use in liquid or powder form and is usually dissolved in sterile water. Most laboratories obtain commercial components, which are mixed in the lab to make a complete culture medium for optimal cell growth. In addition, the culture media are usually supplemented with antibiotics and/or fungicides to inhibit contamination (**Table 1**).

Many continuous mammalian cell lines can be maintained on a relatively simple medium such as MEM supplemented with serum and antibiotics. However, most laboratories use DMEM as mammalian cells can be easily grown in DMEM supplemented with serum as well as antibiotics. When working with specialized cell types, a specialized cell culture medium may be required to maintain the growth of cells such as RPMI-1640 medium that is mostly used to grow cells in suspension such as HL-60 (promyelocytic leukemia) with varying serum amounts.
