The Supreme Court ruled this morning that companies can't patent human genetic sequences.
But they ruled that patents can still be granted on lab-created cDNA sequences.
cDNA is shorthand for complimentary DNA or composite DNA. Based on the ruling, the judges use both terms interchangeably.
DNA is the molecule that our cells use to store information — like a blueprint for the proteins that make up our cells. DNA lives in the cells permanently. It's used as a template to create a molecule called mRNA, which is missing some parts of the genomic DNA code, called introns, and only exists temporarily in the cells.
cDNA is a string of DNA that's not taken directly from the genome but is reverse engineered from mRNA.
In the body, mRNA is used to create essential proteins that make up all parts of your cells and your body.
This is where the scientists come in. They take these mRNAs out of the cell, and instead of using them to make proteins, they copy the sequence and write it out in DNA — cDNA.
This DNA isn't the same as the original in the human cell, because it's missing the introns that weren't copied from the genome.
The court ruling says that because these DNA strands aren't what are found naturally in the body — because they were created by technicians in the lab — these cDNA sequences can be patented.
Some people oppose the ruling because the code itself for the cDNA comes from the human genome, not from being created in the lab. In other words, the lab tech creates the cDNA, but they don't determine the sequence — that comes from the natural human genetic code.