The sample volume, magnetic particle size and cytokine concentration determine the microfluidic volume, sensor size and dimensioning of the magnetic gradient field generators.
Signal to noise can be improved by increasing sample and probe laser power and integrated sample volume [ 141– 143], although particle components, including water at elevated RH, can volatilize and create measurement biases (also common to PAS) when subjected to excessive laser power [ 142, 145].
Table 1 Pure MF samples with different concentrations of magnetic particles Sample Volume ratio of pure MF to liquid paraffin Volume fraction of magnetic particle a 1 8 0.62% b 1 10 0.51% c 1 12 0.43% d 1 14 0.37%.
Pulsed LII measurements represent the average properties of an ensemble of rBC-containing particles in the sample volume.
To achieve random distribution of cells on the filter, the sample volume was increased to 2 mL with particle-free water (Turley 1993), and approximately 3 drops of acridine orange solution (1 mg/mL) were added to the sample.
The sensor presented a reliable (R2 = 0.98) detection of the 10-μm particles down to 7 particles in 10 μL of the sample volume in 15 min.
Where: Vs is the minimum single sample volume per location, expressed in litres Cn, m is the class limit (number of particles / m3) for the largest considered particle size specified for the relevant class 20 is the defined number of samples that could be counted if the particle concentration were at the class limit.
It has been shown that MPIOs exhibit increased relaxation compared to nanometer-sized particles with the same total iron content per unit sample volume [ 34].
Despite this disadvantage, DLS measurement provides statistically more significant overall picture of particle size distribution compared to TEM, since it evaluates the entire sample volume at once.
