Beck N F, Tucker H A
J Dairy Sci. 1977 Apr;60(4):542-5. doi: 10.3168/jds.S0022-0302(77)83900-3.
A radioimmunoassay developed for alpha-lactalbumin was sensitive between 5 and 140 ng alpha lactalbumin. Addition of increasing volumes of milk to assay tubes progressively decreased binding of iodine-125-labeled alpha-lactalbumin to the antisera in a manner which paralleled the binding curve generated by increasing concentrations of standard alpha-lactalbumin. The addition of 10, 20, 30, or 40 ng of alpha-lactalbumin to diluted milk samples gave 90, 100, 105, and 102% recoveries. Alpha-lactalbumin antisera did not crossreact with 1000 ng of bovine casein, blood serum albumin, beta-lactoglobulin, prolactin, or growth hormone. Milk from each of approximately 100 Holstein Friesian cows at different stages of lactation was sampled monthly for 12 mo. Concentrations of alpha-lactalbumin (1.63 mg/ml) and prolactin (24.9 ng/ml) in samples of skim milk collected in the 1st mo of lactation were greater than those in the remaining months of lactation. Monthly concentrations of alpha-lactalbumin and prolactin in skim milk did not change significantly during seasons of the year. The correlation between concentrations of prolactin and alpha-lactalbumin pooled within subclasses of month of lactation within month of year was .08 for 1125 pairs.
针对α-乳白蛋白开发的放射免疫分析对5至140纳克α-乳白蛋白敏感。向分析管中添加体积不断增加的牛奶，会使碘-125标记的α-乳白蛋白与抗血清的结合逐渐减少，其方式与标准α-乳白蛋白浓度增加所产生的结合曲线平行。向稀释的牛奶样品中添加10、20、30或40纳克α-乳白蛋白，回收率分别为90%、100%、105%和102%。α-乳白蛋白抗血清与1000纳克牛酪蛋白、血清白蛋白、β-乳球蛋白、催乳素或生长激素均无交叉反应。在12个月的时间里，每月对大约100头处于不同泌乳阶段的荷斯坦弗里生奶牛的牛奶进行采样。泌乳第一个月采集的脱脂牛奶样品中α-乳白蛋白（1.63毫克/毫升）和催乳素（24.9纳克/毫升）的浓度高于泌乳剩余月份。一年中不同季节，脱脂牛奶中α-乳白蛋白和催乳素的月度浓度没有显著变化。在一年中每个月内按泌乳月份子类汇总的催乳素和α-乳白蛋白浓度之间的相关性，对于1125对数据而言为0.08。
