Minor errors in the process, the continuous decrease of fiber extraction efficiency as well as the potential variation in instrument sensitivity can be eliminated by the use of internal standards.
This "depth-of-search" approach allows for fast recalculation of yield values for variations in instrument parameters.
For comparisons, samples of different genotype were always examined in parallel, using the same reagents and cytometer settings, to eliminate differences resulting from day-to-day variations in instrument performance, reagent stability, etc.
Internal standards, added in-line to samples and standards, were used for quantification and to correct for variations in instrument response.
The signals arising from these standards were used to correct data for variations in instrument performance that occur while a set of samples is being analyzed.
Subjectivity of terms, variations in instrument, organizational differences in work settings, and cultural differences in the perception and reporting of pain and disorders are adduced for the variation in rates of WMSDs in the different studies.
Stained PBMCs were subsequently analyzed on an LSR Fortessa cytometer (BD), using Rainbow Fluorescent Particles (BD) and application settings in BDFACSDiva7 to correct for day-to-day variations in instrument performance.
Alternatively, proper deuterated hopanoids, that is, hopanoids incorporated with enough deuterium atoms to introduce a mass shift high enough to avoid overlap of isotope envelopes of labeled and unlabeled hopanoids, could be included in the samples as internal standards to account for variations in instrument conditions.
The observed differences between electrolyte levels measured using an ABG and an AA may be explained by a combination of factors, including sample transport, dilution of serum samples prior to testing (thus, the use of indirect vs. direct electrodes), and variations in instrument calibration [ 16, 17].
In contrast, there was a considerable degree of variation in the instruments used to evaluate deambulation, fatigue, and sleep disorders.
