Quinolones ELISA

Enzyme immunoassay for the rapid quantitative determination of Quinolones in food.

Background: Quinolones belong to the group of antibiotics. The first identified quinolone, Nalidixic Acid, was discovered as a semi-finished product of the chloroquine synthesis in the year 1962. In the following years many other quinolones were synthesized, characterized and placed on the market. Especially the first fluorinated Norfloxacin represented a breakthrough showing much better pharmacologic properties. Amongst the quinolones Ciprofloxacin actually presents one of the most famous products. Quinolones lead to a ternary complex of the bacterial DNA and their topoisomerase enzymes resulting in cell death of the bacteria. In many countries quinolones are accepted in food production. Since the ingestion of quinolones presents a potential risk to the consumer the maximum amount of quinolone residues in food is regulated in most countries. For example in the EU Regulation No 37/2010 the maximum residue limits for the different quinolones are defined between 30 and 400 µg/kg (ppb) depending on type of matrix and type of quinolone. Thus a monitoring of food with respect to the concentration of quinolones is obligatory.
Quinolones ELISA represents a highly sensitive detection system and is particularly capable of the rapid quantification of quinolone contaminations in milk, serum, egg, honey, shrimps, fish, meat and liver.

Description: The Quinolones quantitative test is based on the principle of the enzyme-linked immunosorbent assay. An antibody directed against quinolones is coated on the surface of a microtiter plate. Quinolones containing samples or standards and a quinolone-peroxidase conjugate are given into the wells of the microtiter plate. The conjugate competes with the quinolones of the samples/standards for the limited number of antibody sites. After 30 minutes incubation at room temperature the wells are washed with diluted washing solution to remove unbound material. A substrate solution is added and incubated for 15 minutes, resulting in the development of a blue colour. The colour development is inhibited by the addition of a stop solution, and the colour turns yellow. The yellow colour is measured photometrically at 450 nm. The concentration of quinolones is indirectly proportional to the colour intensity of the test sample.

Product Features:
- The kit contains reagents for 96 determinations;
- Microtiter plate consisting of 12 strips with 8 breakable wells;
- Ciprofloxacin Standards: 0, 0.4, 1, 4, 10, 40 ng/mL;
- ELISA reader at 450 nm;
- Standard range: 0.4 - 40 ng/mL;
- Sensitivity analytical: 0.13 ng/mL.