For the antibiotic sulphonamide residue test according to Kundrat. The Geobacillus stearothermophilus spore suspension is used in conjunction with the test agar for performing the antibiotic sulphonamide residue test according to Kundrat, Cat. No. 1.10662. The test detects antimicrobial residues such as antibiotics, sulphonamides and other chemotherapeutics in meat and other foodstuffs of animal origin. It is a routine qualitative procedure. The test is based on agar diffusion, using spores of Geobacillus stearothermophilus as test organisms. Antibiotic and sulphonamide residues inhibit the growth of the test organism. Cleaning agents, disinfectants and preservatives do not influence the test.

• This inhibition of growth is indicated by the formation of inhibition zones
• These zones remain purple in colour whilst the rest of the nutrient medium turns yellow