def get_row_col_matrix(row_index_set, col_index_set):
    """
    Returns the resulting matrix when using a row and column of indices (list of tuples)

    row_index_set: the index set that would be taken from wells A-H (or equivalent) on that plate. Should be dim 8 or 16.
    col_index_set: the index set that would be taken from wells 1-12 (or equivalent) on that plate. Should be dims 12 or 24.
    
    """
    if not ((len(row_index_set) == 8 and len(col_index_set) == 12) or (len(row_index_set) == 16 and len(col_index_set) == 24)):
        raise ValueError('Unexpected row or column length. get_row_col_matrix expects the row index set to be the index set from A-H or equivalent (8 or 16 in length) and the col index set to be from wells 1-12 or equivalent (12 or 24 in length). Make sure that you have not swapped the two.')

    index_set = []
    for row_index in row_index_set:
        for col_index in col_index_set:
            index_set.append((row_index, col_index))
    return index_set