In addition to the specimen problems listed above, PCR inhibitors may cause some false-negative results.
Delayed specimen collection, poor specimen collection techniques, specimen transport problems, and lab media contamination are but a few of the practical constraints often influencing the outcomes of the laboratory diagnosis of pertussis.
Note that sample sizes are uneven across metabolic control indicators, because there were some blood specimens with problems for computing levels of HbA1C, Triglycerdies, LDL, and HDL.
With mounting evidence in favour of quantitative assessment of specimens, this problem may need addressing.
A specimen-heating problem, identified by measurements with a thermocouple, was alleviated with the use of thick, aluminum-coated grids.
FNA specimens have unique problems, including small amount of tumor cells within the specimen, and potential specimen preparation artifacts.
FNDs allow us to observe biological specimens without photobleaching problems, and are also useful to obtain practical measurements of the imaging properties of SAX microscopy.
Long may problem specimens like these irritate palaeontologists, museum curators and Wikipedia editors.
Node-by-node correlations between preoperative MRI and histopathological specimens present another problem.
During the impact campaign on H-shaped specimens a major problem with the auxiliary bonding of the substrates to the mounting angles occurred in a number of specimens.
