3.4. Profiling Whole Blood Microsamples

We have developed a protocol that can reliably profile 30 µl of dried whole blood (approximately 50,000 – 100,000 lymphocyte cells) collected by micro-sampling technologies such as Neoteryx tubes (Fig. 17). The micro-sampling technology allows home-based sampling of precise volumes (30 µl) from fingertip blood. The dried blood sample is then mailed to labs at room temperature, where the AIR assay can be used for TCR-BCR analysis. This technique is extensively used in clinical research to monitor metabolites, drugs, and other analytes. It can be conveniently used for AIR RNA repertoire analysis across multiple time points, such as monitoring response to drug treatment in patients with cancer with a simple home-based test [19].

Fig. 17. Processing outline of dried blood samples using Neoterix Microsampling technology.

The AIR RNA Microsample workflow can reliably profile up to 200 of the most abundant clonotypes (with at least 20 UMI counts) and some medium-abundant clonotypes (e.g., 500 with UMI 10 or more). To generate reproducible results, we recommend running the blood microsamples in triplicate (Fig. 16).