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Buffalo (Bubalus bubalis) meat is a major item of export from India but export of beef i.e. meat from cattle (Bos indicus) is prohibited. Also, adulteration of buffalo meat with that of beef (meat from cattle) is a common fraudulent practice because of prohibition on cow slaughter in most states of India. Food analysts require precise identification techniques to implement such regulations. In the present study, a method of DNA extraction by Alkaline lysis from meat samples and speciation of buffalo meat using species specific Polymerase Chain Reaction (PCR) has been reported. Alkaline lysis technique is a rapid method which involves triturating meat with four volumes of 0.2N NaOH, dilution of resultant liquid extract with eight volumes of 0.2N NaOH, heating the mix 75°C for 20 min followed by neutralization with eight volumes of 0.04N Tris HCl. Entire procedure of DNA extraction takes less than 30 min and it is economical as it involves less expensive chemicals. Method was successfully applied in animal byproducts also viz., liver, heart and kidney. For authentication of buffalo meat, pair of primers was designed based on mitochondrial D loop gene nucleotide sequence. PCR amplification using the designed primers gave amplicon of size 482 bp in buffalo and no amplification was detected in closely related species viz., cattle, sheep and goat meat samples. Results of the assay were highly repetitive and reliable. An export sample referred by export regulation authorities was also analyzed by using the Alkaline lysis method of DNA extraction and species specific PCR which enabled authentication of meat within 5 h.

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T helper cytokine and IgG subtype responses were studied in three strains of mice (C57BL/6J, Swiss albino, BALB/c; n=90 per strain) immunized with live Japanese encephalitis virus (JEV) by intraperitoneal (IP), subcutaneous (SC) and peroral (PO) routes. Lymphocytes obtained from the spleens of immunized and control mice were stimulated in vitro with JEV for 48 h and the supernatants were assayed for the presence of the cytokines IL-4 and IFN-c. JEV-specific IgG isotypes were also measured in the sera of immunized mice. T helper cytokine responses in mice immunized with JEV were found to be strain-and route-specific in the three species tested. Moreover, they were also dependent on the type of immunogen used (live vs killed virus), as well as the number of doses administered. C57BL/6J and BALB/c mice were more uniform in their T helper responses compared with the outbred Swiss albino mice and induced a good Th1 response (P<0?001). Among the three routes evaluated, the IP and SC routes consistently elicited a Th1 response compared with the PO route (P<0?001), where an initial Th2-type response reverted to a Th1 response after repeated immunization. Live JEV induced a Th1 response while the commercial killed vaccine induced a predominant Th2 profile.