This tools allows to describe your samples and replicates, producing a tabular file looking like this:

ConditionA	CondA_replicate1
ConditionA	CondA_replicate2
ConditionB	CondB_replicate1
ConditionB	CondB_replicate2
ConditionC	CondC_replicate1
ConditionC	CondC_replicate2
ConditionC	CondC_replicate3

The output file can be used in the tools 'RNASeq samples quality check for transcript quantification' and 'Differential expression analysis'. The names in column 2 must match the names given to the datasets in your history.