Since the first DIPG biopsy has been successfully sorted for single cell analysis a few weeks ago, the researches at Dana-Farber and MGH were able to isolate the RNA from the individual tumor cells. The RNA was then reverse transcribed into cDNA in order to be sequenced. After the reverse transcription the cDNA from each cell was tagged with a barcode (a short unique sequence of base pairs). The code enables bioinformaticians to identify which piece of cDNA came from which cell, later in the process. You can see the workflow depicted in the graphic below.

Before the cDNA is sequenced, the scientists need to make sure that the quality of the sample is good enough and that the reverse transcription actually worked. This is done by an electrophoresis of the sample. You can see the “quality check” electropherogram of the cDNA from DIPG cells in the graph below. The curve suggests an almost perfect sample quality and the sample concentration is more than sufficient for sequencing. This result is better than we could have hoped for!

In the next few days the first cDNA-pool of DIPG cells will be sequenced! The analysis of the data will take some time, but it will give the scientists a better understanding of the DIPG biology and is going to help them to identify new vulnerabilities of this disease.