A colorimetric method for analysis of the red cell content of tissues is described, and compared with an independent radioassay method. The introduced method is based upon acid extraction of tissue, treatment with base, and adsorption of the remaining turbidity with lauryl sulfate. Preliminary data are presented on the reproducibility of the colorimetric method on multiple biopsies of the canin...

Colorimetric phenotypic tests recently gained interest because traditional primary drug susceptibility testing of Mycobacterium tuberculosis isolates takes a long time. We used meta-analysis techniques to review the reliability and accuracy of the nitrate reductase assay (NRA), which is one of the most popular colorimetric methods to detect resistance to first-line drugs. Medline, PubMed, ISI W...

Biologics manufacturing requires the clearance of Host Cell Proteins (HCPs) from recombinant therapeutic protein to acceptable low levels to ensure product purity and patient safety. To ensure adequate removal, a highly sensitive method, commonly in the form of Enzyme-Linked Immunosorbent Assay (ELISA), is necessary to quantify the HCPs amount in process intermediates and drug substance. We rep...

Salicylate concentrations in 3819 sera of apparently healthy voluntary blood donors were determined in view of the significance of this drug in the induction of allergic reactions and its possible interference in platelet function. Two hundred and ninety-five sera were found by a modified colorimetric determination to contain salicylates. The colorimetric determination was compared with a high ...

In this paper, an ultrasound±acetic acid procedure for the simultaneous extraction and hydrolysis of carbohydrates in marine sediments prior to their colorimetric determination is described. The main advantage of the proposed procedure is the improved analytical accuracy achieved. Extraction and hydrolysis are quantitative since the oxidative reactions which cause the underestimation of the tot...

Hepatitis C virus (HCV) infection is the leading cause of liver transplantation in Western countries. Studies of HCV infection using cell culture-produced HCV (HCVcc) in vitro systems require quantification of infectious HCV virions, which has conventionally been performed by immunofluorescence-based focus-forming assay with manual foci counting; however, this is a laborious and time-consuming ...

Aim This study aimed to compare, through dentin microhardness and colorimetric analysis, the chelating effect of 0.2% chitosan solubilized in different acids. Materials and Methods The second and third cuts of the cervical region of maxillary central incisors were divided into four quadrants, resulting in eight specimens, which were treated with 50 μL of solution for 5 min according to their ...

A disposable colorimetric sensor array (CSA) made from printing various chemically responsive dyes was combined with a hand-held device for on-site assessment and monitoring of the freshness of five meat products: beef, chicken, fish, pork, and shrimp. The hand-held device takes advantage of an on-board diaphragm micropump and a commercial 1D CMOS camera (CIS) which enables the real-time collec...

a graphene oxide-terpyridine conjugate (gotc) based colorimetric and fluorescent nano-chemosensor was synthesized. it showed high selectivity and sensitivity for fe2+ and fe3+ ions in neutral aqueous solution over other metal ions such as li+, na+, ba2+, ca2+, al3+, cd2+, co2+, cu2+, hg2+, mn2+, ni2+, pb2+, zn2+, cr3+ and ag+. in absorption spectra, upon addition of fe2+ or fe3+, the sensor dis...

A label-free aptamer-based assay for the highly sensitive and specific detection of Ochratoxin A (OTA) was developed using a cationic polymer and gold nanoparticles (AuNPs). The OTA aptamer was used as a recognition element for the colorimetric detection of OTA based on the aggregation of AuNPs by the cationic polymer. By spectroscopic quantitative analysis, the colorimetric assay could detect ...