Ventral midbrain (VM) dopaminergic progenitor cells derived from human pluripotent stem cells have the potential to replace endogenously lost dopamine neurons and are currently in preclinical and clinical development for treatment of Parkinson’s Disease (PD). However, one main challenge in the quality control of the cells is that rostral and caudal VM progenitors are extremely similar transcriptionally though only the caudal VM cells give rise to dopaminergic neurons with functionality in PD. Therefore, it is critical to develop assays which can rapidly and reliably discriminate rostral from caudal VM cells during clinical manufacturing. Here, we applied shotgun proteomics to search for novel secreted biomarkers specific for caudal VM progenitors compared to rostral VM progenitors and validated key hits by ELISA. From this, we identified novel secreted markers (CPE, LGI1 and PDGFC) significantly enriched in caudal versus rostral VM progenitor cultures, whereas the markers CNTN2 and CORIN were significantly enriched in rostral VM cultures. With this data, we suggest and test in clinical grade samples a panel of coupled ELISA assays that can be applied as a quality control tool for assessing the correct patterning of cells during clinical manufacturing.