Virology Specimen Collection

2016 ◽  
pp. 212-212
Author(s):  
Nanda Maheshwari
Keyword(s):  
Specimen Collection

Specimen Collection Effect in Scanning Electron Microscopy Images

1972 ◽  
Vol 30 ◽  
pp. 448-449
Author(s):  
J. Temple Black ◽  
Jose Guerrero
Keyword(s):  
Surface Morphology ◽  
Secondary Electron Emission ◽  
Secondary Electrons ◽  
Charge Effects ◽  
Material Density ◽  
Specimen Collection ◽  
The Subject ◽  
Curved Paths ◽  
Subject Material ◽  
Microscopy Images

In the SEM, contrast in the image is the result of variations in the volume secondary electron emission and backscatter emission which reaches the detector and serves to intensity modulate the signal for the CRT's. This emission is a function of the accelerating potential, material density, chemistry, crystallography, local charge effects, surface morphology and especially the angle of the incident electron beam with the particular surface site. Aside from the influence of object inclination, the surface morphology is the most important feature In producing contrast. “Specimen collection“ is the name given the shielding of the collector by adjacent parts of the specimen, producing much image contrast. This type of contrast can occur for both secondary and backscatter electrons even though the secondary electrons take curved paths to the detector-collector.Figure 1 demonstrates, in a unique and striking fashion, the specimen collection effect. The subject material here is Armco Iron, 99.85% purity, which was spark machined.

scholarly journals Stability of Novel Plasma Markers Associated with Cardiovascular Disease: Processing within 36 Hours of Specimen Collection

2002 ◽  
Vol 48 (10) ◽  
pp. 1781-1784 ◽  
Author(s):  
Jennifer K Pai ◽  
Gary C Curhan ◽  
Carolyn C Cannuscio ◽  
Nader Rifai ◽  
Paul M Ridker ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Specimen Collection ◽  
Plasma Markers

Collect that Stool! The Impact of Delay in Specimen Collection to NHSN Lab ID C. difficile Events

2019 ◽  
Vol 47 (6) ◽  
pp. S50
Author(s):  
Ashleigh J. Goris ◽  
Kathleen M. McMullen ◽  
Rebecca S. Wade
Keyword(s):  
Specimen Collection ◽  
The Impact

scholarly journals Performance of Unobserved Self-Collected Nasal Swabs for Detection of SARS-CoV-2 by RT-PCR Utilizing a Remote Specimen Collection Strategy

2021 ◽  
Author(s):  
Ron M Kagan ◽  
Amy A Rogers ◽  
Gwynngelle A Borillo ◽  
Nigel J Clarke ◽  
Elizabeth M Marlowe
Keyword(s):  
Return To Work ◽  
Screening Program ◽  
False Negative ◽  
N Gene ◽  
Rt Pcr ◽  
Pooled Testing ◽  
Specimen Collection ◽  
Asymptomatic Patients ◽  
Nasal Swabs ◽  
The Impact

Abstract Background The use of a remote specimen collection strategy employing a kit designed for unobserved self-collection for SARS-CoV-2 RT-PCR can decrease the use of PPE and exposure risk. To assess the impact of unobserved specimen self-collection on test performance, we examined results from a SARS-CoV-2 qualitative RT-PCR test for self-collected specimens from participants in a return-to-work screening program and assessed the impact of a pooled testing strategy in this cohort. Methods Self-collected anterior nasal swabs from employee return to work programs were tested using the Quest Diagnostics SARS-CoV-2 RT-PCR EUA. The Ct values for the N1 and N3 N-gene targets and a human RNase P (RP) gene control target were tabulated. For comparison, we utilized Ct values from a cohort of HCP-collected specimens from patients with and without COVID-19 symptoms. Results Among 47,923 participants, 1.8% were positive. RP failed to amplify for 13/115,435 (0.011%) specimens. The median (IQR) Cts were 32.7 (25.0-35.7) for N1 and 31.3 (23.8-34.2) for N3. Median Ct values in the self-collected cohort were significantly higher than those of symptomatic, but not asymptomatic patients. Based on Ct values, pooled testing with 4 specimens would have yielded inconclusive results in 67/1,268 (5.2%) specimens but only a single false-negative result. Conclusions Unobserved self-collection of nasal swabs provides adequate sampling for SARS-CoV-2 RT-PCR testing. These findings alleviate concerns of increased false negatives in this context. Specimen pooling could be used for this population as the likelihood of false negative results is very low due when using a sensitive, dual-target methodology.

scholarly journals Choice of faecal immunochemical test matters: comparison of OC-Sensor and HM-JACKarc, in the assessment of patients at high risk of colorectal cancer

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Caroline J. Chapman ◽  
Ayan Banerjea ◽  
David J Humes ◽  
Jaren Allen ◽  
Simon Oliver ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Clinical Decision Making ◽  
Full Range ◽  
Clinical Decision ◽  
Detection Rates ◽  
Faecal Immunochemical Test ◽  
Specimen Collection ◽  
Increased Risk ◽  
Immunochemical Test

AbstractObjectivesCurrently, NICE recommends the use of faecal immunochemical test (FIT) at faecal haemoglobin concentrations (f-Hb) of 10 μg Hb/g faeces to stratify for colorectal cancer (CRC) risk in symptomatic populations. This f-Hb cut-off is advised across all analysers, despite the fact that a direct comparison of analyser performance, in a clinical setting, has not been performed.MethodsTwo specimen collection devices (OC-Sensor, OC-S; HM-JACKarc, HM-J) were sent to 914 consecutive individuals referred for follow up due to their increased risk of CRC. Agreement of f-Hb around cut-offs of 4, 10 and 150 µg Hb/g faeces and CRC detection rates were assessed. Two OC-S devices were sent to a further 114 individuals, for within test comparisons.ResultsA total of 732 (80.1%) individuals correctly completed and returned two different FIT devices, with 38 (5.2%) CRCs detected. Median f-Hb for individuals diagnosed with and without CRC were 258.5 and 1.8 µg Hb/g faeces for OC-S and 318.1 and 1.0 µg Hb/g faeces for HM-J respectively. Correlation of f-Hb results between OC-S/HM-J over the full range was rho=0.74, p<0.001. Using a f-Hb of 4 µg Hb/g faeces for both tests found an agreement of 88.1%, at 10 µg Hb/g faeces 91.7% and at 150 µg Hb/g faeces 96.3%. A total of 114 individuals completed and returned two OC-S devices; correlation across the full range was rho=0.98, p<0.001.ConclusionsWe found large variations in f-Hb when different FIT devices were used, but a smaller variation when the same FIT device was used. Our data suggest that analyser-specific f-Hb cut-offs are applied with regard to clinical decision making, especially at lower f-Hb.

scholarly journals Real-time application of automated ribotyping and DNA macrorestriction analysis in the setting of a listeriosis outbreak

2003 ◽  
Vol 131 (1) ◽  
pp. 637-645 ◽  
Author(s):  
T. J. J. INGLIS ◽  
A. CLAIR ◽  
J. SAMPSON ◽  
L. O'REILLY ◽  
S. VANDENBERG ◽  
...  
Keyword(s):  
Environmental Health ◽  
Western Australia ◽  
Food Samples ◽  
Control Measures ◽  
Specimen Collection ◽  
Environmental Specimen ◽  
Initial Control ◽  
Health And Disease ◽  
Automated Ribotyping ◽  
Real Time Application

A cluster of three cases of listeriosis cases occurred against a background of endemic listeriosis in Western Australia. Human and environmental isolates of Listeria monocytogenes obtained during the outbreak investigation were rapidly subtyped by automated ribotyping using an EcoRI protocol and a RiboPrinter®. DNA macrorestriction analysis by pulsed-field gel electrophoresis (PFGE) was used to confirm the relatedness of isolates. Serogroup 1/2 predominated among the food samples and the four clinical isolates from the outbreak cluster were also of this serogroup. All isolates from chicken material were serogroup 1/2 and indistinguishable by ribotype pattern. PFGE subdivided strains of this ribotype into four subtypes. The preliminary analysis had an immediate impact on hypothesis generation, environmental health investigations, environmental specimen collection and initial control measures. Sufficient typing data to guide environmental health and disease control initiatives was generated in less than one week by combining automated ribotyping with PCR-based detection of L. monocytogenes in suspect foodstuffs and an L. monocytogenes DNA probe. There were no further cases of bacteriologically confirmed listeriosis in Western Australia for six months after completion of the investigation.

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