Sensitivity was tested in two ways by running the following sets of swabs: 1) Two-fold
serial dilutions of 1000M cells from 200,000 down to 3,125 cells (1.2 μg to 18.75 ng
based on 6 pg/diploid cell) were prepared and added to swabs ( 6 replicates/dilution,
n=42 total swabs); 2) Mock swab collection to simulate potential DNA amounts from
two donors, across the range from 1 touch to inside of cheek, 1 swipe, 2 swipes, 5
swipes, 10 swipes to 20 swipes of the inside of the cheek ( 3 replicates/collection/donor,
n=36 total swabs). Percentage of alleles detected at each dilution and average peak
height was determined.
Figure 3. Sensitivity study with 1000M cells ranging from 200,000 down to 3,125
showing full profiles obtained for all replicates (n=3/quantity). Average peak heights
decrease as the quantity of cells is reduced (Average ± SD).
Figure 4. Representative
electropherograms from swab
collection study showing full
profiles obtained down to a
single touch of swab to inside
of cheek. Note the Y-axis
scale= 20,000 RFU is for 20
swipes to 2 swipes and is
reduced to 6,000 RFU for 1
swipe and 1 touch.
150 buccal swab sample profiles from a concordance study were used to measure
the deviation of each sample allele size from the corresponding allele size in the
Figure 5. Size difference between allele and corresponding allele in allelic ladder,
n= 5,995 alleles.
Cross Contamination Studies
Fourteen runs were performed to examine run-to-run and channel-to-channel
cross-contamination on the system. An alternating checkerboard pattern across
the sample cartridges was used to test all lanes. Fresh buccal swabs were used
for the sample channels.
Figure 6. Example of a checkerboard run showing no cross-contamination
observed between channels or residual contamination from the previous run where
each blank channel had run a buccal swab sample.
A subset of donor buccal swabs (150 individuals) was processed on four RapidHIT systems. Genotype concordance was checked against reference profiles generated from
the GlobalFiler Express runs on the ABI 9700/3130xL instruments and analyzed with
GeneMapper® ID-X v1.4. In addition, DNA (~1-2 ng/20 μL) from the NIST SRM 2391c
DNA Profiling standard (components A, B, C, and D) were added directly to the STR
reagent vials prior to insertion onto the cartridge and run on the RapidHIT system. All
profiles were concordant with their respective genotypes in the reference database.
NDIS approved GlobalFiler Express Kit validated on the RapidHIT system
SWGDAM developmental validation results showed:
• DNA extraction and purification effectively removes inhibitors
• PCR optimized to provide robust and reliable performance
• Sizing precision capable of 1 bp resolution
• Median peak height ratios ≥ 81%
• No cross-contamination channel-to-channel and/or run-to-run
• Swabs can be retrieved and reprocessed
• 100% genotype concordance of samples analyzed
To demonstrate that swabs
can be retrieved and
buccal swabs were randomly
collected from the cartridges
after being run on the RapidHIT
System. Swabs were inserted
into another cartridge and
reprocessed on the RapidHIT.
Figure 7. Example electropherograms of the DNA profiles
from the re-run of the same