Checklist for quality assessment of brain organoids
| 1. Essential cellular components | |
|---|---|
| Neural stem cell-derived cells, such as neural progenitor cells (Nestin＋ Sox2＋), neurons (Pan-neuronal marker: TuJ1, NeuN), astrocytes, oligodendrocytes, and ependymal cells | 95% or more |
| Optional: non-neural stem cell-derived cells in the brain, such as endothelial cells, pericytes, and microglia | |
| Recommended testing methods: immunostaining or flow cytometry | |
| 2. Neural activity | |
| The proportion of the brain organoid comprised of neurons, or the extent of the response at all electrodes using MEA or voltage sensors | 10% or more |
| Recommended testing methods: Ca2＋ imaging, MEA, voltage sensors, etc. | |
| 3. Gene expression | |
| The organoid should show similarity with a Pearson’s correlation coefficient of 0.4 or more with at least one type of transcriptome profile for actual tissue from a brain region at a given developmental stage, based on bulk RNA-seq | 0.4 or more |
| Recommended testing methods: comparison with region-specific RNA-seq data sets from the Allen Brain Atlas | |
| 4. Detection of neurotransmitters | |
| Neurotransmitters should be detected in brain organoid lysate | |
| Cerebrum: glutamate, GABA | |
| Midbrain: glutamate, GABA, dopamine, serotonin | |
| Spinal cord: glutamate, GABA, acetylcholine | |
| Recommended testing methods: ELISA,HPLC, Raman spectrometry, LC-Mass, etc. | |
MEA: microelectrode array.