Assessment of the inhibition of ricin toxicity by lactose in milk.

The effect of lactose at the concentration typically found in milk (134 mM) on the ability of ricin to inhibit protein synthesis in HeLa cells was studied. Ricin (0.001 to 300 μg/ml) that was either not treated or treated with 134 mM lactose was added to test tubes containing 1 ml of HeLa cells (approximately 3 × 10(5) cells in a low-leucine medium).

Concentration, detection and discrimination of Bacillus anthracis spores in orange juice using aptamer based surface enhanced Raman spectroscopy.

Herein, we developed an innovative label free platform for concentration, detection and discrimination of Bacillus anthracis spores. Based on aptamer capture and surface enhanced Raman scattering detection, we were able to detect 10(4) CFU spores spiked in orange juice and discriminate between spores B. anthracis and B.

Detection and inactivation of saxitoxin in skim milk.

In this study, saxitoxin dihydrochloride in skim milk was reacted with sodium hydroxide and hydrogen peroxide to yield nontoxic 8-amino-6-hydroxymethyl-iminopurine-3(2H)-propionic acid (AHIPA), which was quantified by fluorescence spectroscopy using excitation and emission wavelengths of 330 and 425 nm, respectively. Samples of saxitoxin dihydrochloride (in 20% ethanol, vol/vol) were used as controls. The limits of detection of AHIPA, based on the concentration of saxitoxin prior to inactivation, were 5 and 10 μg/ml for the control and skim milk, respectively.

Comparison of the presence of Shiga toxin 1 in food matrices as determined by an enzyme-linked immunosorbent assay and a biological activity assay.

This study was conducted to compare the identification of Shiga toxin 1 (Stx1) based on its specific biological activity and based on results of a commercial enzyme-linked immunosorbent assay (ELISA) kit. Stx1 was thermally treated for various periods in phosphate-buffered saline, milk, and orange juice. The residual Stx1 concentration was determined with the commercial ELISA kit, and its residual enzymatic activity (amount of adenine released from a 2,551-bp DNA substrate) was determined with a biological activity assay (BAA).