Metabolic Platform, Biochemistry Laboratory, Team for Childhood, Health and Development Faculty of Medicine, Cadi Ayad University, Marrakech, Morocco.
Biochemistry Laboratory, Faculty of Medicine, Cadi Ayad University, Marrakesh, Morocco.
Carbohydr Res. 2020 Dec;498:108179. doi: 10.1016/j.carres.2020.108179. Epub 2020 Oct 17.
A colorimetric microassay for the quantitative determination of galactose in the blood was taken and updated. This method helps in diagnosis and follow-up of several inherited metabolic diseases connected to galactose metabolism deficiency such as galactosemia, glycogenosis, glycosylation, tyrosinemia and citrin deficiency. Galactose assay in the blood presents difficulties due to interference with glucose. In this study, we update a method to get around these difficulties.
This procedure was based on the incubation of whole blood with orcinol in a strongly acidic solution to form a galactose and glucose complexes able to absorb at two different wavelengths.
The standard curve analysis for the individual solutions of these two sugars showed a wide range of linearity from 0 to 200 mg / l. Under optimal experimental conditions, the stirring time of the orcinol is 3 minutes, the heating time of the reaction is 20 minutes at 56 ° C, and the duration of the incubation in the dark is 40 minutes. The analysis is carried out on fresh blood. The maximum absorbance of galactose and glucose is respectively 569 nm and 421 nm. An adapted diagnosis algorithm was developed based on our results.
this method could help in screening and identifying patients with hypergalactosemia that need further investigations. It could represent a promising method for neonatal screening in countries with limited resources.
本文对血液中半乳糖的比色微测定法进行了采集和更新。该方法有助于诊断和随访与半乳糖代谢缺陷相关的多种遗传性代谢疾病，如半乳糖血症、糖原贮积症、糖基化、酪氨酸血症和 citrin 缺乏症。由于葡萄糖的干扰，血液中半乳糖的测定存在困难。在本研究中，我们更新了一种方法来克服这些困难。
该方法基于在强酸溶液中用间苯二酚孵育全血，形成能够在两个不同波长处吸收的半乳糖和葡萄糖复合物。
对这两种糖的单独溶液的标准曲线分析显示出从 0 到 200mg/L 的宽线性范围。在最佳实验条件下，间苯二酚的搅拌时间为 3 分钟，反应的加热时间为 56°C 时 20 分钟，暗孵育时间为 40 分钟。分析在新鲜血液上进行。半乳糖和葡萄糖的最大吸光度分别为 569nm 和 421nm。根据我们的结果开发了一种适应性诊断算法。
该方法有助于筛选和识别需要进一步调查的高半乳糖血症患者。对于资源有限的国家来说，它可能是一种有前途的新生儿筛查方法。
