Research and development advances depend not only on technical sophistication, but on efficiency as well. At Helicos, the power to sequence billions of individual DNA fragments simultaneously is only the beginning. Helicos scientists have developed molecular barcoding techniques to take maximum advantage of the sequencing power enabled by the Helicos® Genetic Analysis System.
The Advantages
Multiplexed barcoded samples run on the HeliScope™ Single Molecule Sequencer saves money and boosts research productivity:
- Increase the number of analyzable samples per run
- Sequence 2.5 Megabases from five different samples per channel at 15X coverage for less than $72 per sample
- Prepare samples simply, without amplification---ligate oligonucleotides to the DNA in your samples and load potentially thousands of samples onto the 50-channel flow cell
- Gain experimental flexibility and avoid unnecessary sequencing redundancy
The Evidence: Targeted Resequencing of five samples in a single channel
Using the Helicos DNA Barcoding protocol, scientists at Helicos were able to multiply the system’s sample throughput five-fold - from 50 samples per run to 250 samples per run – without compromising accuracy or representational bias in a targeted resequencing experiment.
Figure 1. PCR amplicons representing the entire coding sequence of the p53 gene were pooled. The pool was dispensed into five equimolar aliquots, which were independently modified with unique molecular barcodes. The modified samples were combined and sequenced as a mixture in one channel of a 50-channel HeliScope Flow Cell. The representation of the different samples is plotted based on the abundance of reads with a given molecular barcode (1 – 5).
The Approach
The ability of the System to sequence single molecules of DNA coupled with its design typically allows a capacity of greater than 600 to 800 Mb in each of 50 channels on the instrument’s flow cell. The capacity can be deployed to suit the requirements of many experiment types by attaching unique oligonucleotide identifiers to the 3’ end of up to five unique DNA samples. At 15X coverage, varying target sizes can be analyzed, depending on the number of samples multiplexed in a channel.
| Number of Uniquely Identifiable Samples per channel | Number of Uniquely Identifiable Samples per 8-day run | Target Size per Sample (Megabases) |
| 1 | 50 | >26 |
| 2 | 100 | >13 |
| 3 | 150 | >8 |
| 4 | 200 | >6 |
| 5 | 250 | >5 |
Helicos DNA Barcoding – Giving you the plexing power to drive your experiments further, faster.