The objectives of this study were to evaluate different analytical methods determine colostrum quality in dairy cattle, including one laboratory-based method (ELISA) and 4 on-farm tests. We hypothesized that the colostral immunoglobulin G (IgG) concentration using methods, i.e., ELISA (mg/mL), digital Brix refractometer (% Brix), colostrometer (specific gravity mg/mL), an outflow funnel (second...

The refractive index of the circulating blood lymphocytes (LCRI) of healthy young adults vaccinated with typhoid vaccine has been measured by immersion refractometry and phase contrast microscopy. A rise in the LCRI preceeds the rise in the antibody titre by two to three days. A more pronounced rise also occurred in one patient prior to a rejection crises following a kidney transplant.

Assessments of refractivity in a Fabry–Perot (FP) cavity by refractometry often encompass step which the penetration depth light into mirrors is estimated to correct for fraction length no gas can penetrate. However, as it currently carried out, this procedure not always coherently performed. Here, we discuss common pitfall that be reason and provide recipe on how perform FP-cavity-based withou...

A total internal reflection-based differencial refractometer, capable of measuring the real and imaginary parts of the complex refractive index in real time, is presented. The device takes advantage of the phase difference acquired by s- and p-polarized light to generate an easily detectable minimum at the reflected profile. The method allows to sensitively measuring transparent and turbid liqu...