4.2. Cell Culture of HT-29 and DLD-1 Cells

Cell culture HT-29 (HTB-38), DLD-1 (CCL-221) human colorectal adenocarcinoma cell lines and fibroblasts skin cells were acquired from the American Type Culture Collection (ATCC). First cell line was grown in McCoy’s 5A medium (Pan Biotech, Aidenbach, Lower Bavaria, Germany), the second cell line was maintained in RPMI 1640 medium (ATCC, Manassas, VA, USA), and the third one in DMEM (Corning, Kennebunk, ME, USA). The growth supplement for cell culture (fetal bovine serum (FBS—Eurx, Gdansk, Poland)) and antimicrobial substances (penicillin/streptomycin)(Corning, Kennebunk, ME, USA) were added in 10% and 1% concentration, respectively. The incubator asserted appropriate growth conditions which are required for this cell lines: 5% of carbon dioxide, 37 Celsius degree and the humidity between 90% and 95%. The 100 mm plates were used to culture the cells. After a cell line reached about 80–90% confluency, the detachment of cells with 0.05% trypsin containing 0.02% EDTA (Corning, Kennebunk, ME, USA) and PBS (Corning, Kennebunk, ME, USA) was performed. The cells were then reseeded at density 5 × 10⁵ cells per well in six well plate in 1 mL of appropriate medium and after 24 h incubation used in the presented tests.