Yes. riboPOOLs can either be combined by the user or a Combination riboPOOL can be purchased from siTOOLs Biotech. To combine riboPOOLs, determine the ratio of species-specific RNA present in sample and use a corresponding amount of riboPOOL. If this not known, use a 1:1 ratio and optimize accordingly. Up to four riboPOOLs may be combined in a Combination riboPOOL at ratios specified by the user. When combining riboPOOLs, keep total probe amount to 100 pmol/reaction and ensure proportion of hybridization buffer is kept constant i.e. 5 μl in 20 μl final volume.