LDHA and non-small cell lung carcinoma: Therefore, Aldefluor assays followed by FACS analysis were used to assess the presence of a cell population with ALDH activity, and then colony forming assays were used to compare the colony forming capacity of ALDH-positive and ALDH-negative cells in four NSCLC cell lines (NCI-H1299, NCI-H460, NCI-H522 and A549).