Food Safety and Nutrient Detection

Invertase Activity Assay kit provides a simple, sensitive and high-throughput adaptable assay that detects relevant concentrations of Invertase in biological samples or purified/crude enzyme preparations. The assay is based on the enzymatic detection of glucose, one of the hydrolysis products. Detection limit: 20 µU.

There is no requirement for sample pretreatmen or purification when using this kit. The L-amino acid(s) level can be quantified using fluorometric (at Ex/Em = 535/587 nm) or colorimetric (at λ = 570 nm) methods in 96-well plates.

Methionine Assay Kit utilizes an enzymatic mechanism by which metabolism of methionine is coupled with the stoichiometric generation of hydrogen peroxide. A probe generates fluorometric signal that can be quantified at Ex/Em: 535/587 nm. The assay shows greater than 10-fold specificity for methionine over cysteine and greater than 40-fold selectivity over other standard and non-standard amino acids. After utilization of a proprietary Sample Clean-Up Mix, the method is suitable for use in blood samples, and can detect concentrations as low as 0.5 µM, or 25 pmole Methionine.

The NAD Cycling Enzyme Mix in the kit specifically recognizes NADH/NAD in an enzyme cycling reaction. There is no requirement to purify NADH/NAD from samples. The reaction specifically detects NADH and NAD, but not NADP nor NADPH. The enzyme cycling reaction significantly increases the detection sensitivity and specificity. NADt (NAD and NADH) or NADH can be easily quantified by comparing with standard NADH.

Nitric Oxide Fluorometric Assay Kit provides an accurate and convenient measurement of total nitrate/nitrite concentration in a simple two-step process. In the first step nitrate is converted to nitrite by nitrate reductase. In the second step, nitrite reacts with the fluorescent probe DAN (2, 3 diaminonaphthalene). NaOH enhances the fluorescent yield. The fluorescent intensity is proportional to the total nitric oxide production. The kit has been tested with culture media, plasma, and tissue homogenates.

Oxaloacetate Assay Kit provides a simple, sensitive and rapid means of quantifying OAA in a variety of samples. In the assay, OAA is converted to pyruvate which is utilized to convert a nearly colorless probe to an intensely colored (λmax= 570nm) and fluorescent (Ex/Em = 535/587nm) product. The Oxaloacetate Assay Kit can detect 0.1-10nmol (2-200 µM) of OAA.

Phenylalanine Assay Kit provides a quick, simple, accurate method for quantifying PHE in biological samples. In the assay, PHE is reductively deaminated with the simultaneous formation of NADH which reacts with our fluorescent probe to generate fluorescence at Ex/Em=535/587 nm. The assay is linear in the range from 0.1 to 1.0 nmol (2-20 µM) of Phenylalanine.

Phosphatidylcholine Assay Kit is a simple convenient means of measuring Phosphatidylcholine in a variety of biological samples. The kit utilizes an enzyme-coupled assay in which PC is hydrolyzed, releasing choline which is subsequently oxidized resulting in development of the OxiRed probe to generate fluorescence (Ex/Em 535 nm 587 nm) and absorbance (570 nm). Phosphatidylcholine kit measures PC in the range of 0.1 to 10 nmol per sample. PC is present in serum at ~ 0.2-2.5 mM (~50-200 mg/dL).

This kit provides a simple, direct and automation-ready procedure for measuring pyruvate concentration in various biological samples such as blood, cells, culture and fermentation media, etc. In the assay, pyruvate is oxidized by pyruvate oxidase via enzyme reactions to generate color (λ= 570 nm) and fluorescence (at Ex/Em = 535/587 nm). Since the color or fluorescence intensity is proportional to pyruvate content, the pyruvate concentration can be accurately measured. The kit detects 1 µM to 10 mM pyruvate.

In the assay, sarcosine is specifically oxidized to generate a product that converts a colorless probe to a product with intense red color (λmax = 570 nm) and which is also highly fluorescent (Ex/Em = 538/587 nm). Sarcosine is therefore easily detected by either colorimetric or fluorometric methods with detection range 1 – 10000 µM.