Relative error (variability) associated with an improved instrument for measuring gingival crevicular fluid

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Laboratory Science

Background:

• Accurate quantification of small fluid volumes on filter paper is crucial for various diagnostic and research applications.
• Existing methods, such as the Periotron model 600 and the ninhydrin area method (NAM), have limitations in precision and variability.
• Advancements in measurement technology are needed to improve the reliability of these assays.

Purpose of the Study:

• To compare the measurement variability of the new Periotron model 6000 against the previous Periotron model 600.
• To evaluate the Periotron model 6000's performance relative to the ninhydrin area method (NAM).
• To assess the precision of fluid volume measurements on filter paper strips using different methods and sample types.

Main Methods:

• Human serum and a methyl green-dyed water solution were used as sample fluids.
• A precise microliter syringe delivered controlled volumes (0.15-1.05 µL) of fluids to filter paper strips.
• Strips were measured using the Periotron models 6000 and 600, followed by the ninhydrin area method (NAM).
• Coefficients of variation (CV) were calculated to assess measurement variability.

Main Results:

• The Periotron model 6000 demonstrated significantly lower coefficients of variation (CVs) compared to both the Periotron model 600 and the NAM across all tested fluid volumes and types.
• Pooled CVs for the Periotron 6000 were 0.054 (serum) and 0.059 (water), significantly lower than the Periotron 600's 0.116 (serum) and 0.095 (water).
• Comparison with NAM showed pooled CVs of 0.046 (serum) and 0.055 (water) for the Periotron 6000, versus 0.069 (serum) and 0.076 (water) for NAM.

Conclusions:

• The Periotron model 6000 offers superior precision and reduced variability in measuring fluid volumes on filter paper compared to the Periotron model 600 and the NAM.
• The enhanced accuracy of the Periotron 6000 makes it a more reliable tool for quantitative fluid analysis in laboratory settings.
• This advancement in measurement technology has significant implications for improving the consistency and dependability of assays relying on filter paper fluid collection.