Rapid detection methods of antibiotic residue in milk

As dairy farming involves the milking of animals, there is a potential for disease. Commonly that disease is mastitis, the infection (bacterial) of the udder. As a treatment antibiotics are prescribed. The use of these antibiotics has the potential to be carried over into milk if not properly monitored. As such the Australian food standards code Schedule 20 specifies minimum residual limits for milk products. For example, the Maximum Residue Limit (MRL) for Tetracycline in milk is 0.1 mg/kg. Both famers and dairy manufacturers must test for residue before supplying milk. A rapid test for this is a broad spectrum microbiological inhibitor test.

A broad spectrum microbiological inhibitor test is a single well with agar inoculated with a specific bacterial spore and an indicator. Once a sample is added and incubated for a specified period the spores germinate and multiply. As they multiply the bacteria lower the pH and change the colour of the indicator. If, however, antibiotics are present the growth will be slowed or inhibited, and the colour change will be reduced or not occur. To ensure effective interpretation of results a positive and negative control well should be prepared and incubated at the same time.

If the results on the broad spectrum test are positive for antibiotic residue, then the milk must be segregated, and more specific tests carried out to quantify the antibiotic residue.

Our company distributes products of MenidiMedica, a Greece biochemical research company. Contact us for information on below products. 

  • Milk test kits
  • Stains for histology 
  • Gynecological reagents 
  • Culture media 
  • Blood groups 
  • OEM biochemistry reagents and biochemistry analyzer 
  • CHEMELEX LABKIT biochemistry reagents, latex tests, coagulation reagents 
  • GYNEPLUS intrauterine devices 
  • 3GSINCE 2000 food additives