Antibacterial Effects of a Cell-Penetrating Peptide Isolated from Kefir.

Kefir is a traditional fermented milk beverage used throughout the world for centuries. A cell-penetrating peptide, F3, was isolated from kefir by Sephadex G-50 gel filtration, DEAE-52 ion exchange, and reverse-phase high-performance liquid chromatography. F3 was determined to be a low molecular weight peptide containing one leucine and one tyrosine with two phosphate radicals.

Development of a highly sensitive and specific immunoassay for determining chrysoidine, a banned dye, in soybean milk film.

A highly specific and sensitive indirect competitive enzyme-linked immunosorbent assay (icELISA）was developed for the first time for the detection of chrysoidine, a dye banned in soybean milk film. Two haptens with different spacer arms were synthesized to produce antibodies. Both homologous and heterologous immunoassay formats were compared to enhance the icELISA sensitivity.