BD ProbeTec Manual Del Usario página 23

System Cross Contamination and Carryover
An internal study was conducted to evaluate the risk of producing a false positive result in either the same run on the
BD Viper System in extracted mode (within run cross-contamination) or in a subsequent run (between run carryover).
Testing was conducted using negative and positive samples on three BD Viper Systems. Negative samples consisted of
CT/GC Q x Swab Diluent. Positive samples consisted of a representative analyte (at 10
Swab Diluent. The overall rate of cross-contamination (i.e., with alternating columns of positive and negative samples
and a prevalence of 50%) was 0.41% (9/2208). The overall rate of carryover contamination (i.e., carryover between
successive runs when the prevalence was 50% in the previous run) was 0.36% (8/2208). Cross-contamination and
carryover rates across the three BD Viper Systems are summarized in Table 16.
Table 16: Cross Contamination and Carryover Contamination
Assay
Dispense
Mode BD Viper
Selected System
1
2
Dual Assay
3
Overall
1
2
Single Assay
3
Overall
INTERPRETATION OF TABLES
Symbols and Abbreviations
Symbols
(+) positive
(-) negative
# number
% percentage
Abbreviations
A Asymptomatic
CI Confidence Interval
CT Chlamydia trachomatis
CV Coefficient of Variation
EC Extraction Control
FN False Negative
FNU Female Neat Urine
FP False Positive
FS Female endocervical swab
FUPT Female urine in Q
FV Female vaginal swab
GC Neisseria gonorrhoeae
HIV Human Immunodeficiency Virus
I Indeterminate
IFU Inclusion Forming Units
LE Liquid level error
LOD Limit of Detection
MaxRFU Maximum relative fluorescent units
MNU Male Neat Urine
MS Male urethral swab
MUPT Male urine in Q
n number
NA non-applicable
NAAT Nucleic Acid Amplification Test
NPA Negative Percent Agreement
NPV Negative Predictive Value
PA Percent Agreement
PBS Phosphate Buffered Saline
PIS Patient Infected Status
PPA Positive Percent Agreement
PPV Positive Predictive Value
QC Quality Control
S Symptomatic
SD Standard Deviation
SDA Strand Displacement Amplification
STD Sexually Transmitted Disease
TN True Negative
TP True Positive
UPT Urine Preservative Transport
Cross-Contamination
n Positive Results Percent Positive
736 5
736 0
736 4
2208 9
190 0
188 1
188 0
566 1
x UPT
x UPT
n
0.68 736
0.00 736
0.54 736
0.41 2208
0.00 186
0.53 186
0.00 186
0.18 568
22
5
CT EB/mL) spiked into CT/GC Q
Carryover Contamination
Positive Results Percent Positive
1
3
4
8
0
1
0
1
x
0.14
0.41
0.54
0.36
0.00
0.54
0.00
0.18