The influence of anticoagulants on the measurement of total protein concentration in equine peritoneal fluid.

This study explores how two common anticoagulants (K3EDTA and lithium heparin) could affect the accuracy of total protein concentration measurements in horse peritoneal fluid samples. The researchers found that one anticoagulant, K3EDTA, can lead to overestimations when measuring protein levels using a certain method, while lithium heparin does not affect the measurements.

Research Objectives and Methodology

The aim of the study was:

• To determine the impact of two anticoagulants, K3EDTA and lithium heparin, on the measurement of total protein concentration in equine peritoneal fluid samples.
• The comparison was performed by quantifying the protein content through refractometers (devices that measure the degree to which a beam of light changes direction when it travels through a material) and a spectrophotometric method known as the biuret method (a chemical method to detect the presence of protein).

Findings

The study resulted in the following findings:

• The presence of K3EDTA, especially the commercial variant, led to consistent overestimation when measuring total protein concentration using the refractometer method.
• Only high concentrations of K3EDTA in distilled water (above 5 micromol/ml) resulted in an overestimation of protein levels, suggesting that the scope of the interference was linked to the concentration of the K3EDTA.
• In contrast, the presence of lithium heparin did not alter the refractometric readings of total protein, suggesting that this anticoagulant does not interfere with this method for protein measurement.
• When measured by the biuret method, the presence of either anticoagulant did not alter the protein measurement, indicating that this method is unaffected by the presence of the these anticoagulants.

Conclusion

The team concluded that using K3EDTA as an anticoagulant could significantly overestimate total protein values in equine peritoneal fluid samples when measured by refractometry. This could lead to misguided interpretations of protein levels in these samples. Therefore, researchers and medical professionals should be aware of this when choosing a method to measure protein concentrations in equine peritoneal fluid samples.