Accurate and rapid processing of blood or buccal samples collected via swab and paper substrates is critical to the efficient operation of forensic laboratories. The Global Filer ® Express Kit* is an STR multiplex assay enabling direct amplification from reference samples including swabs and paper punches. This application note describes the use of the Formulatrix Mantis to dispense the Global Filer ® Express Kit master mix to the amplification plate with treated buccal punches present.
Methods and Materials
The 1.2 mm treated paper disks with sample were added to the required number of wells prior to the addition of GlobalFiler® Express Kit reagents. The GlobalFiler® Express Kit reagents were processed according to the vendor's instructions for 26 cycle treated paper direct amplification. In brief, the master mix was prepared by combining the following volumes per sample: 6.0 µL master mix, 6.0 µL primer set, and 3.0 µL low-TE buffer. The Mantis liquid handler (Figure 1) was used to dispense 15 µL master mix to the MicroAmp® Optical 96-Well Reaction Plate. The subsequent amplification products were run on an Applied Bioystems 3500xl Genetic Analyzer and analyzed with GeneMapper® ID-X v1 .4 software**.
Out of the 17 treated buccal punches tested, all 17 generated full profiles using a 26 cycle PCR amplification (Figure 2). All amplification co ntrols (two positive and two negative controls) generated expected results, as well.
The combination of the Global Filer ® Express PCR Amplification Kit and the Formulatrix Mantis liquid handler creates an efficient system for generating profiles. The GlobalFiler ® Express chemistry eliminates the need to extract and quantify DNA prior to amplification. The Mantis provides robust and accurate automated dispensing of the Global Filer ® Express Master Mix to the amplification plate with minimal dead volume controlled by intuitive software. Integration of an automated punching robot and a LIMS system would provide a complete system for processing paper punches with complete chain of custody. Future studies will include dispensing GlobalFiler ® Express PCR Amplification reagents with a newer Mantis that features pressurized bottle dispensing to meet the automation needs of modern forensic laboratories.
* For Forensic or Paternity Use Only.
** For Research, Forensic, Paternity and Cell Line Authentication. Not for use in Diagnostic and Therapeutic applications. Global Filer Express is a trademark of Thermo Fisher Scientific Inc. and its subsidiaries.