Scientists say that fast advanced DNA sequencing technologies produce too many errors

99.8 % accuracy of the new methods that can read lengthy sections of genetic material is quite impressive. These methods can reduce the time needed to analyse DNA data, which could speed up genetic studies. However, a new research from the University of Edinburgh revealed that even 99.8 % accuracy equates to millions of mistakes in the results of analysing a genome of more than 3 billion letters.

Studies of the genome are extremely important nowadays. They allow predicting risks of certain diseases and informing people to take some preventive measures to avoid certain conditions that may be encrypted in their DNA. However, the sheer amount of possible mistakes means that information provided to individuals who got their genome examines could be inaccurate. In other words, modern methods of DNA analysis could falsely indicate that a person has a genetic factor that heightens his risk of some sort of disease. Scientists encourage exercising caution when analysing data produced by these new advanced technologies.

But what’s the difference between older and more reliable sequencing technologies and new ones? Well, older methods focused on shorter strings of DNA at a time. Then results would be patched together to reveal the full picture. The entire process would be extremely time and labour consuming, which is not ideal in our fast-paced world. This method could still be used to analyse individual genes of various organisms (both humans and various animals), but it is pretty much inadequate for the full genome analysis. Meanwhile the long-read technologies can read long strings of DNA at a time, which is much faster. And, as scientists now know, less accurate.

Scientists analysed the use of the advanced long-read DNA sequencing technologies o human genome and found that they produce thousands of errors. A ton of those errors remained even after corrective software was used. Scientists say that these errors could have huge implications on results in all areas of DNA sequencing – both research and individual analysis of health risks. Professor Mick Watson, one of the authors of the study, said: “Long-read technologies are incredibly powerful but it is clear that we can’t rely on software tools to correct errors in the data – some hands-on expertise may still be required. This is important as we increasingly use genomic technologies to understand the world around us”.

Scientists are questioning accuracy of new technologies for a reason. While they offer efficiency and time saving, results may vary in terms of accuracy. It is important that all these technologies are thoroughly tested before becoming a go-to in science and medicine.

Source:  University of Edinburgh