Quantitative immunoassay for mink immunoglobulin in serum and milk

Abstract

BackgroundThe significance of maternal immunoglobulin G (IgG) for the resistance against a number of infections affecting the health of young mink offspring is not known. Here, we present a validated immunoassay for quantification of mink IgG in serum and milk, using a commercially available polyclonal goat anti-ferret IgG antibody cross-reactive with mink IgG as both the catching and the detection antibody, in a sandwich format enzyme linked immunosorbent assay (ELISA). Using this ELISA, serum IgG concentrations was analyzed over time in both mothers and kits in order to establish a correlation between maternal IgG serum concentrations and those of the offspring.ResultsIntra-assay coefficient of variation (CV) for a serum sample ranged from 2.15 to 5.97% depending on the dilution, while the inter-assay CV ranged from 5.17 to 17.78%. In addition, the range of milk intra-assay CV was 2.71–5.92%, while the range of the inter-assay CV was 4.20–16.03%. Calibrating the ELISA with purified mink IgG (an in-house preparation purified from mink serum) the lower limit of detection was found to be 5 ng/mL for serum and 1 ng/mL for milk. Both serum and milk showed high precision and good linearity over a two-log dilution range. When comparing the serum IgG concentrations of the mink kits a clear within litter effect was seen, while the mean serum IgG concentrations of litters differed significantly between some of the litters (P = 0.0013). Mean maternal serum IgG concentrations correlated positively with the IgG serum concentration of the corresponding offspring sampled over a 3 week period (R2 = 0.63).ConclusionsA calibrated and reproducible sandwich ELISA for quantifying mink IgG concentrations in both milk and serum with high analytical sensitivity was developed and validated. The results in this study corroborate previous investigations supporting the usability of the ELISA, paving the way for investigations into the importance of maternal IgG in milk and in serum for the welfare and health of the offspring.

Antiplexin D1 Antibodies Relate to Small Fiber Neuropathy and Induce Neuropathic Pain in Animals

“…For interassay coefficients of variation (CVs), 3 samples from 1 patient with plexin D1-IgG and from 2 patients without plexin D1-IgG were analyzed in duplicate in 3 different runs. 12 The difference between the OD of the plexin D1-coated well and that of the noncoated well (the corrected OD value) was calculated, and the test was considered “ELISA-positive” when the corrected OD value was above the mean plus 5 SDs of the 50 plexin D1-IgG-negative controls (30 diseases controls and 20 HCs). 7 …”

In vitro evaluation of potential interference of lokivetmab with protein electrophoresis and immunofixation

“…Perhaps the dilution scheme of the samples or the excipients (L-histidine, histidine HCl monohydrate, trehalose dihydrate, disodium EDTA dihydrate, L-methionine and polysorbate 80), which are included in the Cytopoint ® vial, created a matrix effect responsible for this finding. The inter-assay coefficient of variation for albumin was 1.87 % which is considered acceptable (< 10 %) and should not have affected the results [15]. These excipients may have been a possible limitation for this study but we were unable to purchase lokivetmab without them.…”

Dam characteristics associated with pre-weaning diarrhea in mink (Neovison vison)

“…This finding suggests that mink kits in litters with restricted access to milk supply have increased risk of PWD. This may be due to a decreased transfer of humoral immunity (IgG) by the milk, which recently in mink has been shown to be litter specific and to some extend correlated to the IgG levels in the dam [ 17 ]. The statistically significant contribution to the multivariable model of ‘farm PWD status’ is very likely a proxy for the presence of other important risk factors on the farms than the ones included in our study, e.g.…”

“…Severe weight loss of the dam and restriction of feed allowance during the winter and late gestation period have been shown to increase the risk of PWD [ 14 – 16 ]. Large litters and litters from young dams have been found to have increased risk of PWD [ 15 ], and the immune status of the dam may also be of importance for development of PWD [ 17 , 18 ]. Concurrent with PWD, mastitis is often a problem on the farms and has been hypothesized to be associated with the syndrome [ 2 ].…”