My laboratory needed 11 new cell lines for experiments. We decided to order from one of the Seoul cell banks. We obtained cell lines with supporting documentation. I need Hela cells for my experiment, passage before 30. But Hela from the bank has passage number 99. Moreover, in documents there are results of mycoplasma test for each line. One of the lines has positive result! Is it normal to obtain old or contaminated cells from cell banks? Where do you prefer to get cell lines?