A TEST used to identify ailments such as Hepatitis and AIDS will now help the Maharashtra Police determine whether the meat they have seized is that of a cow. The portable meat testing machines the Maharashtra Police is planning to buy will use the ELISA (Enzyme-linked Immunosorbent Assay) Test, which is also used as a quality control check in various industries and for drug testing at the workplace.
Since the test will take 30 minutes to identify if a sample of meat is beef or not, as opposed to a DNA test which can take from a few days to several weeks, the Maharashtra government believes it will curb harrassment of people arrested on suspicion of carrying beef. The ‘screening test’ will also reduce the workload of the Forensic Science Laboratory (FSL), which does a DNA test of all samples seized by the police. Once the testing kits are provided, those samples testing negative will not be sent to the FSL.
Krishna Kulkarni, acting director of state FSL, said, “ELISA test has been in use for a long time. In the late ’80s, it was used to identify the presence of HIV. It is also used to identify several fungi and bacteria-related diseases. This time, however, we will be using its principles to find out if a particular meat sample is beef or not.”
Explaining the test procedure, Kulkarni said that wells (small test tubes) of a microtiter plate are coated with cow antibodies. Antibodies are proteins used by the immune system to neutralise pathogens.
Later, the scientists extract antigens from the meat sample that the police have seized. Antigens induce an immune response in an organism and cause it to produce antibodies. The antigens are then added to the microtiter plate that already has a cow’s antibodies. “An antigens-antibodies reaction is allowed to take place. Later, enzymes and substrate are added to this serum and the mixture is allowed to incubate for at least 15-20 minutes,” he said.
“Eventually, a simple colour test determines if the meat sample is beef. If, after the incubation period, the colour of the mixture does not change, it means there was no reaction between the antigen and beef antibody. It means the two samples do not belong to the same meat type. Since antibodies are from beef samples, the antigen taken from the sample seized by the police is therefore not beef,” said Kulkarni. “If the colour of the serum changes to yellow, it means that both the antigen and antibodies are beef samples,” he added.
Since the ELISA test is a pathology screening test, samples that test positive will be sent to the FSL’s DNA department for confirmation of the results. After the DNA test, a final report will be provided to the police. The report, based on the genetic pattern, will be admissible as evidence in a court of law. “ELISA is only a screening test. However, it will save a lot of time and also reduce the number of samples that will be sent to the FSL,” said Kulkarni. The test kits will be given to as many as 45 forensic investigation vehicles of the Maharashtra Police.
The Maharashtra FSL will be getting the beef detection kits from Hyderabad-based chief scientific officer Jayant Bhanushali. “In addition to beef, Bhanushali also has a buffalo meat detection kit,” said Kulkarni.He added that there have been advances in this field across the world and in the US, there is a company that has kits to identify in 30 minutes if a sample of meat is from a horse.
A senior FSL official said they will begin work with the beef detection kits once they are available. A home department official said, “The process of acquiring the kits has begun and we hope to get them in the next two to three months.”