mda mb 231 cancer cell lines and on mcf10a normal mammary epithelial cells is measured using an mtt kit tacs u2122 trevigen u00ae inc exponentially growing cells are plated in a 96 well plate at a density of 8 u00d7 10 3 cells per well and allowed to attach for 24 hours complete growth medium is then replaced with 100 u03bcl of rpmi serum free medium gibco invitrogen ny containing one of various doses 50 0 10 0 1 0 0 5 0 1 u03bcm of the test latrunculin compound culture continues at 37 u00b0 c under 5 co 2 after 72 h of culturing the cells are treated with mtt solution 10 u03bcl well at 37 u00b0 c for 4 hours the color reaction is stopped by adding the solubilization stop solution 100 u03bcl well incubation continues at 37 u00b0 c until complete dissolution of the formazan product absorbance of the samples is determined at 570 nm with an elisa plate reader biotek vt the number of cells per well is calculated against a standard curve prepared at the start of each experiment by plating various concentrations of cells as determined by hemocytometer ic 50 for each compound is calculated using non linear regression of log concentration versus number of cells well implemented in graphpad prism 5 0 cultrex u00ae cell invasion assay anti invasive activities are measured using trevigen 39 s cultrex u00ae cell invasion assay 50 u03bcl of basement membrane extract bme coat is added to each well after incubation for 4 h at 37 u00b0 c in 5 co 2 mda 50 000 mb 231 cells in 50 u03bcl of serum free rpmi or leibovitz 39 s l 15 medium are.