Background: The microbial testing platform, Peel Plate™, was developed with Baird Parker ingredients for Staphylococcus aureus (SA) specificity. After rehydrating with 1 mL of the diluted food sample, Peel Plate SA is incubated for 24-48 h at 35-37 °C and observed for purple colonies.
Objective: A validation study was performed to evaluate Peel Plate SA for enumeration of S.
Testing milk for antibiotics before acceptance into dairies is required by the U.S. Pasteurized Milk Ordinance.
View Article and Find Full Text PDFA qualitative 3 min one-step assay for detecting beta-lactam, sulfonamide, and tetracycline antibiotics was validated following milk screening test guidelines developed by FDA-CVM, AOAC-RI, and IDF. The validated 90% detection levels with 95% confidence were: penicillin G 2 part per billion (ppb); amoxicillin 4 ppb; ampicillin 9 ppb; ceftiofur plus metabolites 50 ppb; cloxacillin 9 ppb; cephapirin 15 ppb; sulfadimethoxine 8 ppb; sulfamethazine 9 ppb; chlortetracycline 34 ppb; oxytetracycline 53 ppb; and tetracycline 42 ppb. Detection levels were lower than U.
View Article and Find Full Text PDFBackground: Peel PlateTM Enterobacteriaceae Bacteria (EB) is dried selective media on a 47 mm plastic plate that produces enzyme substrate colored colonies on rehydration and incubation for 24 h and up to 48 h at 37 ± 1°C.
Purpose: The method validation compared quantification of EB to reference methods ISO 21528:2017 Parts 1 and 2.
Methods: Matrixes compared were whole milk, skim powdered milk, vanilla ice cream, butter, infant formulas (soy- and dairy-based), infant cereals ± probiotic, environmental sponge swab of stainless steel surface, and poultry carcass rinse with two different peptone buffers.
The primary goal of bioprocess cell line development is to obtain high product yields from robustly growing and well-defined clonal cell lines in timelines measured in weeks rather than months. Likewise, high-throughput screening of B cells and hybridomas is required for most cell line engineering workflows. A substantial bottleneck in these processes is detecting and isolating rare clonal cells with the required characteristics.
View Article and Find Full Text PDFThe kinetics of the reaction OH/OD + SO were studied using a laser flash photolysis/laser-induced fluorescence technique. Evidence for two-photon photolysis of SO at 248 nm is presented and quantified, and which appears to have been evident to some extent in most previous photolysis studies, potentially leading to values for the rate coefficient k that are too large. The kinetics of the reaction OH(v = 0) + SO (T = 295 K, p = 25-300 torr) were measured under conditions where SO photolysis was taken into account.
View Article and Find Full Text PDFThe kinetics of the reaction OH/OD(v = 1,2,3) + SO were studied using a photolysis/laser-induced fluorescence technique. The rate coefficients OH/OD(v = 1,2,3) + SO, k, over the temperature range of 295-810 K were used to determine the limiting high-pressure limit k. This method is usually applicable if the reaction samples the potential well of the adduct HOSO and if intramolecular vibrational relaxation is fast.
View Article and Find Full Text PDFPeel Plate™ EC is a low-profile plastic, 47 mm culture dish with an adhesive top that contains a dried medium with Gram-negative selective agents and with enzyme substrate indicators for β-galactosidase (coliform) and β-glucuronidase (Escherichia coli). The method provides a conventional quantitative coliform (red) and E. coli (blue/purple/black) count with simple rehydration and incubation for 24 ± 2 h at 35 ± 1°C, while providing a total coliform result, sum of E.
View Article and Find Full Text PDFPeel Plate™ AC (aerobic count) is a low-profile plastic 47 mm culture dish with adhesive top that contains a dried standard plate count medium with oxidation/reduction indicator triphenyl tetrazolium chloride (TTC) that turns red with dehydrogenase enzyme activity of growing aerobic bacteria. The method provides a conventional quantitative count with simple rehydration and incubation for 48 ± 3 h at 35 ± 1°C for most food matrixes and 32 ± 1°C for 48 ± 3 h for dairy products. Dairy matrixes claimed and supported with total aerobic count data are whole milk, skim milk, chocolate milk (2% fat), light cream (20% fat), pasteurized whole goat milk, ultra-high temperature pasteurized milk, nonfat dried milk, lactose-reduced milk, strawberry milk, raw cow milk, raw goat milk, raw sheep milk, condensed skim milk, and vanilla ice cream.
View Article and Find Full Text PDFFood Addit Contam Part A Chem Anal Control Expo Risk Assess
August 2015
Aflatoxin M₁ contamination in dairy products is a risk when feedstuff contaminated with aflatoxin B₁ produced by moulds is consumed by milk-producing animals. Milk can be screened for aflatoxin M₁ at the European Union maximum limit of 50 ng l⁻¹ by a lateral flow test, the MRLAFMQ (Aflatoxin M1) Test. The method takes 15 min with no milk dilution or a sample preparation step.
View Article and Find Full Text PDFA simple, cow-side test for the presence of drug residues in live animal fluids would provide useful information for tissue drug residue avoidance programs. This work describes adaptation and evaluation of rapid screening tests to detect drug residues in serum and urine. Medicated heifers had urine, serum, and tissue biopsy samples taken while on drug treatment.
View Article and Find Full Text PDFThe photolysis of glyoxal has been investigated in the 355-414 nm region by dye laser photolysis coupled with cavity ring-down spectroscopy. Absolute quantum yields of HCO, ΦHCO, were determined using the reaction of chlorine atoms with formaldehyde as an actinometer. The dependence of the quantum yield on pressure was investigated in 3-400 Torr of nitrogen buffer gas and at four temperatures: 233 K, 268 K, 298 K and 323 K.
View Article and Find Full Text PDFThe formation of HCO and of H in the photolysis of glyoxal have been investigated over the wavelength ranges 310-335 nm for HCO and 193-340 nm for H. Dye laser photolysis was coupled with cavity ring-down spectroscopy for HCO, and with laser induced fluorescence spectroscopy for H. Absolute quantum yields were determined using actinometers based on (a) Cl2 photolysis and the Cl + HCHO reaction for HCO and (b) N2O photolysis (and O(1)D + H2) and CH2CO photolysis (and CH2 + O2) for H.
View Article and Find Full Text PDFA variant of cavity-enhanced Raman spectroscopy (CERS) is introduced, in which diode laser radiation at 635 nm is coupled into an external linear optical cavity composed of two highly reflective mirrors. Using optical feedback stabilisation, build-up of circulating laser power by 3 orders of magnitude occurs. Strong Raman signals are collected in forward scattering geometry.
View Article and Find Full Text PDFPork tissue samples that tested positive and negative by the Charm II tetracycline test screening method in the slaughter plant laboratory were tested with the modified AOAC International liquid chromatography tandem mass spectrometry (LC-MS-MS) method 995.09 to determine the predictive value of the screening method at detecting total tetracyclines at 10 μg/kg of tissue, in compliance with Russian import regulations. There were 218 presumptive-positive tetracycline samples of 4,195 randomly tested hogs.
View Article and Find Full Text PDFBackground: Because of the ability of blood-oxygen-level-dependent (BOLD) MRI to assess blood oxygenation changes within the microvasculature, this technique holds potential for evaluating early perisynovial changes in inflammatory arthritis.
Objective: To evaluate the feasibility of BOLD MRI to detect interval perisynovial changes in knees of rabbits with inflammatory arthritis.
Materials And Methods: Rabbit knees were injected with albumin (n=9) or saline (n=6) intra-articularly, or were not injected (control knees, n=9).
The Charm 3 SL3 beta-Lactam Test is a 3 min receptor-based lateral-flow Rapid One-Step Assay (ROSA) that detects the six beta-lactam drugs of concern approved for dairy cattle in the United States. The method is a biochemical formulation change of the SL3 beta-Lactam Test evaluated and approved in 2007. The Charm 3 SL3 was evaluated under the AOAC Research Institute Performance Tested Method (PTM) program following the protocol of the U.
View Article and Find Full Text PDFAppl Environ Microbiol
December 2010
Coliphages are microbial indicators specified in the Ground Water Rule that can be used to monitor for potential fecal contamination of drinking water. The Total Coliform Rule specifies coliform and Escherichia coli indicators for municipal water quality testing; thus, coliphage indicator use is less common and advances in detection methodology are less frequent. Coliphages are viral structures and, compared to bacterial indicators, are more resistant to disinfection and diffuse further distances from pollution sources.
View Article and Find Full Text PDFPhotoexcitation of glyoxal at wavelengths over the range of 395-414 nm was observed to initiate a chemical reaction that produces the HCO radical in addition to the photolytic production of HCO. The technique of dye laser flash photolysis coupled to cavity ring-down spectroscopy was used to determine the time dependence of the HCO radical signal, analysis of which suggests that the chemical source of HCO is the self-reaction of triplet glyoxal (HCO)2(T1) + (HCO)2(T1) --> 2 HCO + (HCO)2. As the photoexcitation wavelength increases, the production from the triplet glyoxal reaction increases relative to that of HCO from direct photolysis, and at 414 nm, the dominant source of HCO in the system is from the self-reaction of the triplet.
View Article and Find Full Text PDFBackground: A consecutive series of seventy-six patients (101 hips) underwent primary open reduction, capsulorrhaphy, and innominate osteotomy for late-presenting developmental dislocation of the hip. They were between 1.5 and five years old at the time of surgery, which was done between 1958 and 1965.
View Article and Find Full Text PDFThe SL3 beta-Lactam Test is a 3 min, receptor-based lateral flow Rapid One Step Assay (ROSA) that detects 5 of 6 beta-lactam drugs approved for dairy cattle in the United States. The method was evaluated through the AOAC Research Institute Performance-Tested Method program following a U.S.
View Article and Find Full Text PDFFood allergies affect an estimated 10 to 12 million people in the United States. Some of these individuals can develop life-threatening allergic reactions when exposed to allergenic proteins. At present, the only successful method to manage food allergies is to avoid foods containing allergens.
View Article and Find Full Text PDFBackground: A consecutive series of seventy-six patients (101 hips) underwent primary open reduction, capsulorrhaphy, and innominate osteotomy for late-presenting developmental dislocation of the hip. They were between 1.5 and five years old at the time of surgery, which was done between 1958 and 1965.
View Article and Find Full Text PDFAlthough biomechanical signals generated during joint mobilization are vital in maintaining integrity of inflamed cartilage, the molecular mechanisms of their actions are little understood. In an experimental model of arthritis, we demonstrate that biomechanical signals are potent anti-inflammatory signals that repress transcriptional activation of proinflammatory genes and augment expression of anti-inflammatory cytokine IL-10 to profoundly attenuate localized joint inflammation.
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