An automated microbiological method for the measurement of vitamin B12

Protein binding assays for an accurate differentiation of vitamin B12 from its inactive analogue. A study on edible cricket powder

Inactive analogues of vitamin B12 (cobalamin, Cbl) can mimic the active Cbl in food if using the traditional microbiological measurements. Thus, overestimated Cbl was recently revealed in edible insects employing immunoaffinity adsorption, HPLC-separation and mass spectrometry (https://doi.org/10.1016/j.foodchem.2021.129048). Here we demonstrate the utility of a convenient binding assay to evaluate Cbl in edible cricket powders. The assay employed the Cbl-specific protein intrinsic factor (IF) and the analogue-detecting protein haptocorrin. The excessive analogues had a weak affinity for IF, resulting in a modest overestimate of Cbl. This overestimate was corrected by a novel mathematical procedure, based on the ratio of analogue/Cbl in the sample and their relative affinities for IF. We found that 100 g of cricket powders contained 40-60 µg of analogues and 0.75-2.2 μg of Cbl. This result was confirmed by HPLC. A correct approach to Cbl-measurements is essential for nutritional assessment of any analogue-containing food.

A Comprehensive Study: Traditional and Cutting-Edge Analytical Techniques for the Biomarker Based Detection of the Micronutrients & POC Sensing Directions for Next-Generation Diagnostic

Micronutrient deficiency is wide spread and highly affects morbidity, mortality, and well-being of human beings. Micronutrient deficiency gradually manifests into diseases, which effects pathophysiology directly or indirectly. There is an imprecision in the diagnosis of micronutrient deficiency because of two causes; the selection of the standard biomarker and the diagnostic technique used. In appropriate diagnosis could increase the severity of the disorder. Instead of a single a combination of biomarkers can give more stringent results for micronutrient testing. Several traditional analytical techniques are used for diagnosis but HPLC, ELISA & LCMS/MS are most sensitive and reliable methods used by CLSIA-certified labs. However, these techniques require well-equipped, centralized laboratory facilities. The diagnostic era moves toward the Point of Care Testing (POCT), a boon in emerging diagnostics, breaking all paradigms of traditional analytical techniques. POCT led us toward the development of biosensors, which encompasses many techniques like paper-based sensors, microfluidic chip, wearable devices, and smartphone-assisted diagnostics, which become more popular diagnostic tools. This outlook summarizes the micronutrients like vitamins A, B5, B6, B7, B9, B12 C, D, and E and Minerals like iron, calcium, zinc, magnesium, and sodium; along with its biomarkers, analytical techniques, and point of care innovation in micronutrients.

Stability Indicating RP-HPLC method for Methylcobalamin determination in different dosage forms: application to photodegradation kinetics and pH-rate profiling

A stability-indicating RP-HPLC method for methylcobalamin determination was developed. Stress degradation under variable conditions was carried out. Methylcobalamin had pronounced susceptibility to hydrolysis under acidic, alkaline, and photolytic conditions; further study of photolytic degradation kinetics and pH rate profiling over pH range 2-11 was carried out. Photodegradation of methylcobalamin followed zero-order kinetics with half-life 0.99hour equivalent to 1971.53 lux. Methylcobalamin followed pseudo first order kinetics upon exposure to acidic and alkaline hydrolysis with highest stability at pH 5 and least stability at pH 2. Optimization of chromatographic conditions was performed using two level full factorial design, chromatographic analysis was executed using Inertsil^® column (250×4.6 mm, 5μm) maintained at 25^◦ C. Elution was carried out using 25mM potassium dihydrogen phosphate (pH adjusted with phosphoric acid to 3.8): methanol: acetonitrile (55:35:10, v/v) as mobile phase. The flow rate was 1.0 mL/min. Detection was carried out at 220 nm using diode array detector. The method was validated as per ICH guidelines; the linearity was over concentration range 2-160 μg/mL with coefficient of determination 0.9995. The method was effectively applied for determination of methylcobalamin in Cobalvex^® ampoule, cobal^® tablet, cobal-F^® tablet and methyltechon^® oral dissolvable film without interfering from excipients within run time six minutes. This article is protected by copyright. All rights reserved.

Semielectronic turbidimeter for automated monitoring of bacterial growth in test tubes

An automated turbidimeter for measuring bacterial growth in ordinary test tubes is described. The device records and prints adsorbance, expressed as Klett units, of 60 cultures every 15 min. Provision is made for either aerobic or anaerobic incubation. The device is adaptable to modification, depending upon local requirements and availability of computation facilities.

Microbiological turbidimetric methods: linearization of antibiotic and vitamin standard curves

Procedures were devised to linearize the usually curved calibration lines for turbidimetric microbiological assays. Three new equations relating concentration of drug and turbidity are described; two are for antibiotic assays and one for vitamin assays. One equation is for antibiotic assays employing Klebsiella pneumoniae as the test organism. The accuracy of interpolation from the three equations was studied by means of appropriate mathematical models based on erthromycin, chlortetracycline (K. pneumoniae), and cyanocobalamin assays. The accuracy of the new expressions was significantly superior to those used previously, and they are of general applicability.