DELVOTEST SP-NT 25 COUNT

Delvotest® SP NT is a standard diffusion test for the detection of residues of antibacterial substances (antibiotics and sulphonamides) in milk. The test consists of ampoules or plates of 96 wells each containing a solid agar medium seeded a standardised number of spores of Bacillus stearothermophilus var. calidolactis together with required nutrients for growth purposes and an antifolate trimethoprim. The medium is colored purple by the pH indicator bromocresol purple. Milk samples that are free from antibacterial substances or contain them below-specified levels will, when added to the test at the level of 0.1 ml and incubated at 64 ° C, allow germination and growth of the bacteria. This will lead to a change in the color of the indicator from purple to yellow. When the milk sample contains antibacterial substances at or above the test sensitivity, growth is inhibited, and as a result, the color remains predominantly purple.