Application

• For quantitative determination of lactose and evaluation of drug effects on lactose metabolism.

Key Features

• Sensitive. Use as little as 20 µL samples. Linear detection range in 96-well plate: 17 to 2000 µM lactose for colorimetric assays and 6 to 100 µM for fluorimetric assays.
• Convenient and high-throughput. Robust and homogeneous “mix-incubate-measure” type assay. Can be readily automated on HTS liquid handling systems for processing thousands of samples per day.

Method

• OD570nm, or FL530/585nm

Samples

• Biological (milk), food and agriculture etc

Species

• All

Procedure

• 30 min

Size

• 100 tests

Detection Limit

• 6 µM

Shelf Life

• 6 months

More Details

• Lactose (C₁₂H₂₂O₁₁), also called milk sugar, is a disaccharide that consists of β-D-galactose and α/β-D-glucose through a β1-4 glycosidic linkage. Lactose is the major sugar and makes up 2–8% of milk. Simple, direct and high-throughput assays for lactose determination find wide applications. BioAssay Systems assay uses specific enzyme-coupled reactions in which lactose is cleaved and the resulting galactose forms a colored product. The color intensity at 570nm or fluorescence intensity at 530nm/585nm is directly proportional to the lactose concentration in the sample.

I would like to know if I can use the optical density at 540nm to read my samples.

The signal at 540nm is only about 2/3 of the signal at 570 nm, but you still can use it. However, you will lose sensitivity.

Xue, H et al. (2020). Lactose-induced chronic diarrhea results from abnormal luminal microbial fermentation and disorder of ion transport in the colon. Frontiers in Physiology, 11, 877. Assay: Lactose in rat feces.

Snyder, N. A., Palmer, M. V., Reinhardt, T. A., & Cunningham, K. W. (2019). Milk biosynthesis requires the Golgi cation exchanger TMEM165. Journal of Biological Chemistry, 294(9), 3181-3191. Assay: Lactose in mouse skimmed milk.

Vabbilisetty, P and S Xue-Long (2014). Liposome surface functionalization based on different anchoring lipids via Staudinger ligation. Organic and Biomolecular Chemistry 12(8): 1237-44. Assay: Lactose in liposome.

Kwon DH et al (2012).Dietary protein restriction induces steatohepatitis and alters leptin/signal transducers and activators of transcription 3 signaling in lactating rats. J Nutr Biochem 23(7):791-9. Assay: Lactose in rat milk.

To find more recent publications, please click here.

If you or your labs do not have the equipment or scientists necessary to run this assay, BioAssay Systems can perform the service for you.

– Fast turnaround
– Quality data
– Low cost

Please email or call 1-510-782-9988 x 2 to request assay service.