def collect_celltypes(ys):
    """
    Collect all available celltypes given all dataset labels
    :param ys: list of dataset labels
    :return: list of available celltypes
    """
    ct_list = [list(set(y['Celltype'].tolist())) for y in ys]
    celltypes = set()
    for ct in ct_list:
        celltypes = celltypes.union(set(ct))
    celltypes = list(celltypes)
    return celltypes