def check_rack_labels(df_map):
    """Removing '.' for rack labels (causes execution failures)
    """
    cols = ['TECAN_sample_labware_name', 'TECAN_primer_labware_name', 'TECAN_dest_labware_name']
    for x in cols:
        df_map[x] = [y.replace('.', '_') for y in df_map[x].tolist()]
    return df_map