There are two main schools of thought when it comes to DNA sequencing. Some people prefer to use sanger sequencing, a method of sequencing DNA using the dideoxynucleosides inside. Others prefer to use next generation Sequencing, a method of organising DNA to find the order of nucleotides in targeted DNA cells.
As you can imagine, there are a lot of similarities between these two procedures. However, they both produce different results. So, what is the difference between these two methods?
Speed
Any scientist will want to complete their experiment as quickly as possible. When it comes to sequencing DNA, the sanger sequencing method is the one that produces results faster. However, this is only for a low yield result. Increase the sample size or sensitivity level, and you will find the NGS is a quicker process.
Accuracy
Of course, the results you find from your DNA testing are useless if it isn’t correct. That is why many researchers choose to use the sanger sequencing procedure over NGS. While it may take a bit longer to sequence, sanger sequencing has an accuracy rate of 99.99%. This means that you will spend less time redoing your work with such highly reliable results.
Cost
Unfortunately, this aspect does not swing in Sanger sequencing’s favour. In fact, the cost difference between the two methods is much larger than you may think. It costs on average £500 per Mb for sanger sequencing, while next generation sequencing only costs the user £0.50 per Mb. As you can see, it does not matter how reliable Sanger sequencing can be. Most scientists will rather pay a smaller fee and have to rerun the experiment for accuracy than have to shoulder the financial burden. This is clearly a point in NGS’s corner.
Data
One additional aspect that you want to consider when sequencing DNA is the number of results you receive at the end of your trial. The sad fact is sanger sequencing isn’t scalable and can only work with between five hundred and seven hundred bps. While these results will be accurate, there will be times when you have to repeat the process for patients that want a comprehensive list of results. At that price point, you may struggle to achieve this.
Fortunately, NGS generates more data over time, no matter the quantity of DNA that needs sequencing. As a result, you may find this data output more beneficial.
Discovery Power
Before you start any experiment, you need to have a good idea of the outcome. With next-generation sequencing, you know that there is a high discovery power. Unfortunately, Sanger sequencing is low discovery. This means that you are more likely to produce results with NGS. When you are preparing to demonstrate an experiment, it is best that you actually produce some sort of result, even if it takes longer. Therefore, NGS wins this round too.
Conclusion
While there are some clear advantages to using next generation sequencing, there are times when sanger is the preferred method. Take these points on board next time you have to make a decision between the two.