$probeset = bless( {
                     '_genechip' => 'Human Genome U133A Array',
                     '_probeset_id' => '1007_s_at',
                     '_affy_date' => '2004-12-07',
                     '_chipcode' => 'HG_U133A',
[ ...}
                     '_trans_id' => '????',
                     '_exons_num' => '????',
                     '_organism' => 'Homo sapiens'
                   }, 'Probeset' );