Descriptor schemas

When working with the biological data, it is recommended (and often required) to properly annotate samples. The annotation information attached to the samples includes information about organism, source, cell type, library preparation protocols and others.

The annotation fields associated with the samples or related sample files are defined in the descriptor schemas. This tutorial describes the descriptor schemas that are attached to the sample objects, raw sequencing reads and differential expressions files.

Other available descriptor schemas can be explored at the Resolwe-bio GitHub page. Customized descriptor schemas can be created using the Resolwe SDK.


When a new data object that represents a biological sample (i.e. fastq files, bam files) is uploaded to the database, the unannotated sample ( presample) is automatically created. When annotation is attached to the presample object, this object is automatically converted to the annotated sample. To annotate the sample, we need to define a descriptor schema that will be used for the annotation. Together with the descriptor schema, we need to provide the annotations (descriptors) that populate the annotation fields defined in the descriptor shema. The details of this process are described in the Resolwe SDK documentation.

To annotate the sample in a GEO compliant way, we prepared the sample annotation schema. An example of the customized descriptor schema is also available.


To annotate raw sequencing reads we have prepared corresponding reads descriptor schema.

Differential expression

To define the default thresholds for p-value, log fold change (FC) and to describe which samples are used as cases and which as controls in the calculation of differential expression we have prepared diffexp descriptor schema.