False‐negative solid‐phase platelet crossmatch results due to prozone phenomenon

Transfusion ◽  
2020 ◽  
Vol 60 (12) ◽  
pp. 3055-3059
Author(s):  
Rachel K. Horton ◽  
Micah D. Zuccarelli ◽  
Laurie L. Wakefield ◽  
Margaret A. DiGuardo ◽  
Manish J. Gandhi ◽  
...  
Keyword(s):  
Solid Phase ◽  
False Negative ◽  
Phase Platelet ◽  
Prozone Phenomenon

scholarly journals Syphilitic Balanitis of Follmann: Laboratory Pitfalls

2020 ◽  
Vol 78 (3) ◽  
pp. 265-268
Author(s):  
Filipa Tavares Almeida ◽  
Filomena Azevedo ◽  
Carmen Lisboa
Keyword(s):  
Infected Patient ◽  
False Negative ◽  
Previous History ◽  
Syphilis Infection ◽  
Flocculation Test ◽  
History Of ◽  
Antibody Titers ◽  
Lattice Network ◽  
Antigen Antibody ◽  
Prozone Phenomenon

We report a case of early syphilis, presenting as balanitis and papular syphilides in an HIV-infected patient, with a previous history of syphilis infection, which demonstrated a false negative VDRL testing due to a prozone phenomenon. This false negative response results from overwhelming antibody titers, which interfere with the proper formation of the antigen-antibody lattice network, necessary to visualize a positive flocculation test.

scholarly journals Reducing the risk of misdiagnosis of indirect ELISA by normalizing serum-specific background noise: The example of detecting anti-FGFR3 autoantibodies

2019 ◽  
Author(s):  
Christian Peter Moritz
Keyword(s):  
False Positive ◽  
Background Noise ◽  
Indirect Elisa ◽  
Solid Phase ◽  
False Negative ◽  
Rabbit Antiserum ◽  
Growth Factor Receptor ◽  
Normalization Method ◽  
Enzyme Linked Immunosorbent Assay ◽  
False Positive Diagnosis

Indirect enzyme-linked immunosorbent assay (ELISA) is an important diagnostic method as it enables the quantification of the presence of autoantibodies in human blood sera. However, unspecific binding of antibodies to the solid phase causes considerable serum-specific background noise (SSBN), involving the risk of false positive diagnosis. Therefore, we present a simple and concise, yet obvious proof-of-principle of a recently suggested normalization method. The method is based on subtracting SSBN by using non-coated ELISA wells as a control for each serum-of-interest. We performed ELISA to quantify anti-fibroblast growth factor receptor 3 (FGFR3) antibody levels in three positive controls (two anti-FGFR3-positive patients and a rabbit antiserum against FGFR3) and 58 negative controls (healthy blood donors). In all subjects, we found considerable unspecific reactivity which strongly varied among subjects. The conventional normalization method was not able to balance this strong SSBN, as demonstrated by 2/58 false positive healthy controls and one FGFR3-positive patient that was hidden in the noise (false negative). SSBN normalization reduced the frequency of false-positives to 0/58. Further, all three anti-FGFR3-positive sera were successfully detected and even doubled their z-score used to determine positivity. Albeit occupying more space on the ELISA plate, we strongly recommend considering this normalization method when working with blood sera. To better put the idea across to the community, we depict the SSBN issue and its solution in a graphic scheme. We conclude that SSBN normalization increases the sensitivity and specificity of indirect ELISA and thereby reduces the risk of false positive and false negative diagnosis.

Rapid Detection of Salmonellae in Foods Using Immunoassay Systems

1986 ◽  
Vol 49 (2) ◽  
pp. 92-98 ◽  
Author(s):  
GEORGE F. IBRAHIM ◽  
MARY J. LYONS ◽  
RETA A. WALKER ◽  
GRAHAM H. FLEET
Keyword(s):  
Solid Phase ◽  
False Negative ◽  
Food Samples ◽  
Negative Results ◽  
Cultural Method ◽  
False Negative Results ◽  
Salmonella Serotypes ◽  
Cost Efficient ◽  
Positive Results ◽  
Additional Sample

A standard cultural method, radioimmunometric (RIMA) and enzyme immunometric (EIMA) assays were compared for detection of salmonellae in 235 food samples. The immunoassays used titanous hydroxide as the solid-phase, commercial Spicer-Edwards salmonella polyvalent H antisera (SEA) or pooled antisera produced against 10 salmonella flagellins (PFA). Nineteen food samples were positive for Salmonella by the standard cultural method. These as well as one additional sample were also positive for Salmonella by RIMA and EIMA. No false-negative results were obtained from the immunoassays using PFA, whereas two false-negative results were observed when SEA was used. The incidence of false-positive results when SEA and PFA were used were, respectively, 3.0 and 0.9% with RIMA and 2.6 and 0.9% with EIMA. The immunoassays were also able to detect 77 Salmonella serotypes when grown alone or in association with other species of Enterobacteriaceae, in mannitol selenite cystine broth. Both immunoassays performed reliably on enrichment cultures stored under refrigeration for up to 9 d. Also, of 6 non-motile salmonellae, 5 were detectable by the immunoassays. The immunoassays were simple, rapid and cost-efficient.

Murine monoclonal antibody adsorbed onto vinylidene fluoride floccules used to eliminate antibody interference in "sandwich"-type immunoassays.

1989 ◽  
Vol 35 (8) ◽  
pp. 1743-1746 ◽  
Author(s):  
E S Newman ◽  
L A Moskie ◽  
R N Duggal ◽  
D M Goldenberg ◽  
H J Hansen
Keyword(s):  
Monoclonal Antibody ◽  
Vinylidene Fluoride ◽  
Solid Phase ◽  
Simple Procedure ◽  
False Negative ◽  
Igg Antibody ◽  
Negative Results ◽  
False Negative Results ◽  
Phase Complex ◽  
Sandwich Type

Abstract We have previously reported that human anti-mouse IgG antibody (HAMA) can cause false-positive and false-negative results in "sandwich"-type monoclonal antibody (MAb) assays. To eliminate HAMA interference in "sandwich"-type MAb assays, we investigated the use of MAb on solid-phase, vinylidene fluoride floccules, which we have previously used as a solid-phase second antibody for RIA. The simple procedure effectively removes greater than 95% of HAMA from the most positive serum we have obtained from patients hyperimmunized to murine MAb, and it allows for accurate quantification of carcinoembryonic antigen. The solid-phase complex, added to blood, effectively removes HAMA and (or) "HAMA-type" heterophilic antibody from the sera or plasma.

False-negative reactions due to incorrect image analysis by automated solid-phase red blood cell adherence assay

Transfusion ◽  
2010 ◽  
Vol 50 (10) ◽  
pp. 2282-2282
Author(s):  
Steven H. Kang ◽  
Elizabeth Gloster ◽  
Melissa White ◽  
Irena Swiderski ◽  
Leon Bradley
Keyword(s):  
Image Analysis ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Solid Phase ◽  
False Negative ◽  
Cell Adherence ◽  
Adherence Assay

False‐negative ELISA result for HIV antibody due to an apparent prozone phenomenon

1987 ◽  
Vol 147 (1) ◽  
pp. 42-42 ◽  
Author(s):  
Allison Imrie ◽  
Susan Best ◽  
Ronald Penny ◽  
David A. Cooper
Keyword(s):  
False Negative ◽  
Prozone Phenomenon ◽  
Elisa Result

scholarly journals CovidArray: A Microarray-Based Assay with High Sensitivity for the Detection of Sars-Cov-2 in Nasopharyngeal Swabs

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2490
Author(s):  
Francesco Damin ◽  
Silvia Galbiati ◽  
Stella Gagliardi ◽  
Cristina Cereda ◽  
Francesca Dragoni ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Solid Phase ◽  
Quantitative Polymerase Chain Reaction ◽  
False Negative ◽  
Rna Extraction ◽  
High Sensitivity ◽  
Great Sensitivity ◽  
Viral Rna ◽  
Analytical Sensitivity ◽  
Negative Results

A new coronavirus (SARS-CoV-2) caused the current coronavirus disease (Covid-19) epidemic. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) is used as the gold standard for clinical detection of SARS-CoV-2. Under ideal conditions, RT-qPCR Covid-19 assays have analytical sensitivity and specificity greater than 95%. However, when the sample panel is enlarged including asymptomatic individuals, the sensitivity decreases and false negatives are reported. Moreover, RT-qPCR requires up to 3–6 h with most of the time involved in RNA extraction from swab samples. We introduce CovidArray, a microarray-based assay, to detect SARS-CoV-2 markers N1 and N2 in the nasopharyngeal swabs. The method is based on solid-phase hybridization of fluorescently-labeled amplicons upon RNA extraction and reverse transcription. This approach combines the physical-optical properties of the silicon substrate with the surface chemistry used to coat the substrate to obtain a diagnostic tool of great sensitivity. Furthermore, we used an innovative approach, RNAGEM, to extract and purify viral RNA in less than 15 min. We correctly assigned 12 nasopharyngeal swabs, previously analyzed by RT-qPCR. Thanks to the CovidArray sensitivity we were able to identify a false-negative sample. CovidArray is the first DNA microarray-based assay to detect viral genes in the swabs. Its high sensitivity and the innovative viral RNA extraction by RNAGEM allows the reduction of both the amount of false-negative results and the total analysis time to about 2 h.

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