Application of Yingtai Vacuum Centrifugal Concentrators in Forensic DNA Sample Concentration

Application of Yingtai Vacuum Centrifugal Concentrators in Forensic DNA Sample Concentration 

Concentration is a common method used in extracting trace and challenging forensic samples. Common techniques include the Amicon centrifugal ultrafiltration tube, DNA Clean & Concentrator-5 kit, and the Microcon-100 method. However, these methods require transferring DNA templates between different columns, which inevitably leads to DNA loss and increases the risk of contamination.

Vacuum centrifugal concentration is a modified physical concentration method that utilizes centrifugal force, heating, and vacuum to evaporate liquids, thereby concentrating and drying DNA. After reaching a set rotational speed, vacuum suction is initiated, and the evaporated liquid is collected in a sealed container. This effectively prevents sample cross-contamination and laboratory pollution. The method allows simultaneous concentration of multiple samples, with the concentration factor adjustable by controlling the volume of deionized water, offering simplicity and flexibility.

In a study involving 48 forensic DNA templates, the vacuum centrifugal concentrator achieved concentration levels ranging from 4.4x to 7.7x. The resulting electropherograms exhibited significantly increased peak heights, improved peak balance, and resolved certain nonspecific bands and false homozygotes. The number of alleles identified increased from 1,334 to 1,942, and the number of effectively typed samples rose from 19 to 27. The quality of some sample electropherograms was notably improved.

Features of Vacuum Centrifugal Concentration Technology

1.Shorter Concentration Time: At 45°C, drying 50 μL of liquid using a constant-temperature mixer takes over 8 hours, while vacuum centrifugal concentration requires only about 1 hour.

2.Sealed Environment: Both the concentration and liquid recovery processes occur in a closed environment, reducing the risk of laboratory contamination.

3.Ease of Operation: The method is straightforward, with flexible concentration factors, minimal DNA loss, and the entire concentration process completed in a single tube.

4.Cost-Effectiveness: A single vacuum centrifugal concentrator can be applied to existing extraction and purification methods for long-term use.

Vacuum centrifugal concentration is suitable for DNA samples with large template volumes, few inhibitors, and suboptimal original electropherogram typing. It improves the success rate of analyzing trace and challenging forensic samples.

The Yingtai Vacuum Centrifugal Concentrator can process multiple samples simultaneously without the risk of cross-contamination. The system allows up to 36 programmable settings, and the vacuum level can be adjusted based on different samples. The device uses a Pirani vacuum gauge to display the chamber’s vacuum level in real time, ensuring accurate control. The vacuum range is adjustable from 0.1 to 1,000 mbar, with a precision of 0.1 mbar. The rotational speed of the machine can also be adjusted to suit different samples. Rotor replacement is tool-free, and the device can be integrated with freeze-drying systems.