Abstracts of the Scientific Posters, 2013 AACC Annual Meeting ...

Automation/Computer Applications
Tuesday, July 30, 9:30 am – 5:00 pm
Results:16 Variations of 5 parameters (3 salts and 2 solvents) were used to determine
their influence on the MS/MS peak areas of the four Immunosuppressants when
from spiked whole blood. Enhancement of the signal intensity and/or signal_to-noise
values (S/N) for the Immunosuppressant extraction was determined for the chemical
parameters Acetonitrile, LiCI, Ascorbic acid, NH4OH, Carbonate, Isopropanol. A
negative influence was found for Methanol, Ethanol, Formic acid, NaCholate and
Citrate. Ammonium acetate and GDTA were rather neutral.
Conclusions: The automated “pipette-and-shake” workflow allowed for the efficient
DoE optimization of the parameters involved in the sample preparation procedure.
Using this approach with the extraction plate, a set of 15 parameters (e.g., pH, salt,
solvent) could be screened with only 4 experiments without changing the protocol
for the liquid handling workstation. An optimized mixture for the extraction of
Immunosuppressants Cyclosporine D, Everolimus, Sirolimus and Tacrolimus
from whole blood was selected. An improved sensitivity for all four analytes of
approximately 3-4 fold was achieved by using the Design-of-Experiment (DoE)
approach.
A-84
Direct Sampling From Pediatric Collection Tubes on the Abbott
Architect Clinical Chemistry Instruments
M. S. Warner 1 , C. Wilson 2 . 1 Winston-Salem State University, Winston-
Salem, NC, 2 UNT, Denton, TX
Background The ability to sample directly from pediatric collection tubes eliminates
the need to transfer small volume samples to sample cups for testing and maintaining
sample identity integrity. A feasibility study was performed to find an acceptable dead
volume for several peditube types investigated.
Method Testing was performed using five typical, readily available pediatric collection
tubes, (four contained Lithium Heparin), and three sample tubes with false bottoms.
Architect sample cups were tested as controls. Assays were AlbG, CaC, GluC, Na-C,
K-C, Cl-C and TP with 2.0uL to 15.0uL sample volumes. The initial sample volume
was based on each assay’s insert, with an 8uL sample overaspiration volume (23uL
for ISE assays), plus a 50uL dead volume. Assays were ordered with 5 reps per assay.
BioRad LiquiChek Level 2 was used for sample and was pipetted directly into the
tubes. The weight of each tube was recorded before and after sample was added.
Architect sample cup and false bottom tubes were placed directly into sample carriers.
The remaining five pediatric tubes were placed in Becton-Dickinson tube extenders
in sample carriers. After testing, tubes were weighed again and the weight recorded.
Volume remaining in tubes was calculated from the density of the sample. Tubes with
aspiration errors before 5 reps completed were re-tested with increased 10uL dead
volume. Process continued until 5 reps for each assay completed with acceptable
results. Study was repeated with a new sample volume based on increased dead
volume. After the run with five replicates completed successfully, the process was
repeated in single replicates for all tubes without aspiration errors. The tubes were
re-weighed and weights recorded. Process was repeated until an aspiration error was
obtained for each tube. The volume remaining in the last tube with acceptable results
was calculated from the density of the sample and the dead volume for each tube
determined. Pediatric collection tubes used were Becton Dickson BD 365958, Becton
Dickson BD 365987, Greiner 450479, Sarstedt 16.443.100 and Terumo T-MLHG.
False bottom tubes were Sarstedt 60.613.010, Sarstedt 60.614.010 and Sarstedt
60.617.010.
Results This study was successful if all five replicates initially run completed without
any aspiration errors and with acceptable results. Six replicates for each assay, a total
of 42 tests, completed without any aspiration errors and with acceptable results.
Suggested dead volumes for the tubes were determined to be 85uL for BD-365958,
93uL for BD-365987, 75uL for Greiner 450479, 77uL for Sarstedt 16.443.100, 78uL
for Terumo T-MLHG and 74uL for Sarstedt 60.613.010, Sarstedt 60.614.010 and
Sarstedt 60.617.010. The gel layer in the pediatric collection tubes and the shape of the
false bottom tubes contributed to the dead volume required to get acceptable results.
Conclusion An acceptable dead volume can be assigned for each of the specific tube
types that were investigated. The use of validated peditubes allows direct sampling of
critical volume samples, eliminating the manual transfer step and the possibility of
patient misidentification and potential labeling errors when the sample is transferred
from a peditube to a sample cup.
A-85
Validation of DRG:Hybrid XL, a Fully Automated Random Access
Analyzer for Immunoassays and Clinical Chemistry, for 17-OH
Progesterone
M. Herkert 1 , S. Passig 1 , B. Uelker 1 , T. Dudek 1 , C. Lauf 1 , H. Vaupel 1 , F.
Becker 1 , R. Hellmich 1 , C. E. Geacintov 2 . 1 DRG Instruments GmbH,
Marburg, Germany, 2 DRG International Inc., Springfi eld, NJ
The DRG:HYBRID-XL ® Analyzer is an innovative and unique instrument that
allows the simultaneous measurement of up to 20 samples, with up to 40 different
immunoassays and clinical chemistry parameters including turbidimetric tests. After
loading of ready-to-use reagent cartridges, typical assay times range from 10-90
minutes. The barcoded master curve can be adjusted by 2-point recalibration.
Objective: To validate the Hybrid XL, the steroid hormone 17-α-Hydroxyprogesterone
(17-OHP) was analyzed in human serum. 17-OHP is produced by both the adrenal
cortex and gonads. In adult non-pregnant women, 17-OHP concentrations vary over
the menstrual cycle with concentrations being higher in the luteal phase than in the
follicular phase. The hormone is of clinical interest because it is released in excess
in congenital adrenal hyperplasia, and is moderately elevated in 11-β-hydroxylase
deficiency.
Methodology: The 17-OHP assay is a solid phase enzyme-linked immunosorbent
assay, based on competitive binding. 25 μl of serum are incubated for 1 hour at 37°C
in a coated well together with 200 μl of enzyme conjugate. Thereby, endogenous 17-
OHP of a patient sample competes with a 17-OHP-horseradish peroxidase conjugate
for binding to the coated antibody. Unbound components are washed off, and 200 μl
of TMB substrate is added to the well to start the color reaction. After 30 min, 150 μl
TMB are transferred from the well to a cuvette, and the optical density is measured
at 645 nm (450 nm reference wave length). Quantification is done based on a master
standard curve that is barcoded on the kit box.
Validation: 17-OHP can be quantified from serum and plasma (EDTA, heparin,
citrate) on the DRG:Hybrid XL. The dynamic range of the assay is between 0.11-20
ng/mL. The sensitivity was determined according to EP-17A. The limit of detection
is 0.11 ng/mL and the limit of quantification is 0.18 ng/mL. The mean within-run
precision (determined with 6 samples covering the measuring range of the assay) is
3.98% (n=16; range from 2.65-6.23%). The mean between-run precision is 9.16%
(16 different runs; n=32; range from 7.05-14.98%). The mean recovery is 101.1%
(n=5; range from 88.4-114.9%). The mean linearity is 100.9% (n=5; range from 76.7-
111.2%). Cross-reactivity was evaluated by determining the effective concentration
at 50% displacement of various compounds that are structurally related to
17-α-Hydroxyprogesterone. Cross-reactivity is below 0.01% for Estriol, Aldosterone,
Androstenedione, Testosterone, DHEA, DHEA-S, Prednisone, Cortisol, and Estradiol.
Cross-reactivity for Progesterone was 1.2%. Bilirubin and Hemoglobin (up to 0.5 mg/
mL) and Triglycerides (up to 30 mg/mL) have no influence on the assay results. The
accuracy of the 17-OHP assay on the DRG:Hybrid XL instrument was determined
by comparison with 17-OHP manual Elisa (EIA-1292) from DRG Instruments. The
correlation coefficient is 0.998 (n=118; y=1.053x; sample concentration, range 0.11-
19.86 ng/mL). Normal values range between 0.12-2.49 ng/mL (males) and 0.06-3.93
ng/mL (females).
Conclusion: The performance of new DRG Hybrid XL analyzer to reproducibly
quantify 17-OHP is in good agreement with the manual ELISA from DRG Instruments.
A-86
Automation in the pre analytical phase and sample flow: Gains in
productivity and safety in a Brazilian clinical laboratory
F. C. S. Roseiro, A. R. Bertini, C. Pereira, C. A. O. Galoro, J. Y. Ferraro, C.
C. T. Silva. DASA, São Paulo, Brazil
Introduction: The workflow of samples within the pre-analytical laboratory stage
is already well defined. However, laboratory workloads are constantly growing at
the same time that laboratories are under pressure to contain or lower costs. The
sample reception department of CientíficaLab Laboratory (DASA), business unit that
provides laboratory services to the Brazilian Public Market, received in March 2010
almost 25,000 tubes per day, with about 2 million tests to be processed in the lab. This
department had at that time 34 FTEs, with a productivity indicator of 56,923 tests
/ FTE / month. All activities were processed manually, including bar code reading,
sorting and aliquoting. A decision to improve and automatize most of these tasks was
made.
CLINICAL CHEMISTRY, Vol. 59, No. 10, Supplement, 2013
A23