This study evaluated the performance of the HemaSpot dried blood collection device using the Abbott RealTime HIV-1 assay. Whole blood samples containing different known concentrations of HIV-1 were dried on HemaSpot devices and tested using the Abbott assay. The HemaSpot device demonstrated 100% detectability of samples containing 5000 or 2500 copies/mL of HIV-1, 92% detectability of samples containing 625 copies/mL, and a limit of detection of 690 copies/mL. Intra-run and inter-run reproducibility were good, not exceeding 0.17 and 0.14 log copies/mL, respectively. The HemaSpot performed well with automated extraction and showed potential as a dried blood specimen for HIV-1

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Performance of HemaSpot device using the Abbott RealTime HIV-1 assay (RT)
Danijela Lucic Ph.D.1, Christine Herman1, Jeanette Hill2, Gavin Cloherty1, Shelley Hossenlop2
1Abbott Molecular , Des Plaines, IL; 2Spot On Sciences, Austin, TX
Background Results Conclusions
• Normal whole blood was obtained from
ProMedDx (Norton, Ma).
• Third HIV-1 World Health Organization
(WHO) International Standard (IS) was
used to generate whole blood panels
targeting the following concentrations:
5000cps/ml, 2500cps/ml, 1250cps/ml,
625cps/ml and 312cps/ml.
• Eighty microliters was spotted on each
HemaSpot device and allowed to air dry for
3hours. Panels were stored at 8C overnight.
• Full HemaSpot was incubated in 1.3mL of
proprietary elution buffer for 45min..
• Prior to sample extraction each sample was
gently vortexed and transferred to m2000sp
for extraction.
• RNA extraction was performed using 1ml
protocol and the performance of the RT
assay was assessed.
• Intra and Inter-run reproducibility was
evaluated across 3 different runs.
• In resource limited settings, the use of
dried blood specimens for HIV-1 diagnosis
and monitoring has become a necessity for
improved patient management.
• Several studies have evaluated the
performance of the most commonly used
device, Whatman 903, with RT assay.
• The objective of this study was to evaluate
the performance of the RT assay with
HemaSpot device.
• In addition, this study evaluated the
performance of HemaSpot device with
m2000sp automation.
Figure 1: HemaSpot device
• Ease of use with automation, short drying
time prior to testing as well as the LOD
makes HemaSpot device a suitable
specimen type for RT testing on the m2000
platform.
• Future studies with this device, including
direct comparison to Whatman 903, are
ongoing.
Table 1: Intra-run Reproducibility
Table 2: Inter-run Reproducibility
Methods
• One hundred percent detectability was
observed at 5000 cps/ml (n=6), 2500
cps/ml (n=7) and 1250 (n=15) cps/ml while
92% detectability was observed at 625
cps/ml (n=12) and 44% detectability at 312
cps/ml (n=9).
• Probit analysis demonstrated that the LOD
with 95% probability was 690 cps/ml.
• Intra-run reproducibility did not exceed
0.17 log copies/mL at any level (Table 1).
• Inter-run reproducibility did not exceed
0.14 log copies/mL at any level (Table 2).
Figure 2: HIV-1 detectability at 5000, 2500, 1250, 625 and
312 cps/mL.
Expected
log copies/mL
Observed
inter-run mean log
copies/mL
Inter-run SD
log copies/mL
3.7 3.71 0.13
3.4 3.38 0.14
3.1 3.23 0.14
2.8 3.04 0.06
Expected log
cps/mL
Run 1 mean log
cps/mL (SD)
Rune 2 mean
log cps/mL (SD)
Run 3 mean log
cps/mL (SD)
3.7 3.67 (0.1) 3.66 (0.12) 3.67 (0.17)
3.4 3.38 (0.17) 3.37 (0.16) 3.39 (0.1)
3.1 3.28 (0.12) 3.23 (0.17) 3.16 (0.12)
2.8 3.09 (0.11) 3.01 (0.01) 3.03 (0.01)