scholarly journals Novel Direct Assay for Acetyl-CoA:α-Glucosaminide N-Acetyltransferase Using BODIPY-Glucosamine as a Substrate

2015 ◽  
pp. 11-18 ◽  
Author(s):  
Yoo Choi ◽  
Alexander B. Tuzikov ◽  
Tatyana V. Ovchinnikova ◽  
Nicolai V. Bovin ◽  
Alexey V. Pshezhetsky
Keyword(s):  
Direct Assay

Mn2+-mediated magnetic relaxation switching for direct assay of ctDNA in whole blood via exonuclease III assisted amplification

2021 ◽  
Vol 330 ◽  
pp. 129340
Author(s):  
Yunyun Hu ◽  
Xin Guo ◽  
Peilin Gu ◽  
Qin Luo ◽  
Yang Song ◽  
...  
Keyword(s):  
Whole Blood ◽  
Magnetic Relaxation ◽  
Exonuclease Iii ◽  
Direct Assay

scholarly journals A rapid direct assay for the determination of the separate activities of the three arylsulphatases of Aspergillus oryzae

1977 ◽  
Vol 166 (3) ◽  
pp. 411-413 ◽  
Author(s):  
G R J Burns ◽  
C H Wynn
Keyword(s):  
Phenolic Compounds ◽  
Aspergillus Oryzae ◽  
Substrate Specificities ◽  
Direct Assay ◽  
Assay Procedure ◽  
Rate Of Hydrolysis ◽  
Hydrolysis Of ◽  
Potential Use

1. The three arylsulphatases of Aspergillus oryzae exhibit pronounced kinetic differences and substrate specificities. Arylsulphatase I hydrolyses all substrates tested, whereas arylsulphatase III will not hydrolyse tyrosine O-sulphate or phenolphthalein disulphate. Arylsulphatase II does not hydrolyse p-nitrophenyl sulphate or phenolphthalein disulphate at appreciable rates in the absence of added phenolic compounds. Phenols such as tyramine increase the rate of hydrolysis of these substances by this enzyme 1000-fold. At pH 6.9 arylsulphatase I exhibits an apparent Km of 0.1 mM for p-nitrophenyl sulphate, whereas the Km of arylsulphatase III for this substrate is 1 mM. 2. These differences were utilized to develop an assay procedure which can be used to determine the separate activities of the three enzymes present in mixtures. This assay has potential use as a means of examining the relative activities of the three enzymes in investigations of the differences in the mechanisms regulating their synthesis.

CHRONIC DIARRHEA AND FAILURE TO THRIVE DUE TO INTESTINAL DISACCHARIDASE INSUFFICIENCY

PEDIATRICS ◽  
1964 ◽  
Vol 34 (6) ◽  
pp. 807-813
Author(s):  
John T. Clarke ◽  
Warren Quillian ◽  
Harry Shwachman
Keyword(s):  
Lactic Acid ◽  
Intestinal Mucosa ◽  
Clinical Condition ◽  
Chronic Diarrhea ◽  
Failure To Thrive ◽  
Normal Activity ◽  
Mucosal Tissue ◽  
Disaccharidase Activity ◽  
Direct Assay

An infant with chronic diarrhea due to suspected generalized disaccharidase insufficiency is described. The clinical condition of the infant improved following the removal of lactose and sucrose from the diet. The fermentative and acidic stool with free lactose and lactic acid also improved. However, the infant was too ill to undergo direct assay of intestinal mucosal tissue for disaccharidase activity or for challenge with offending sugars. Postmortem tissue assay revealed less than 10% of normal activity for lactase, sucrase, maltase, and isomaltase in the intestinal mucosa.

scholarly journals Three routine methods for measuring high-density lipoprotein cholesterol compared with the Reference Method

1996 ◽  
Vol 42 (5) ◽  
pp. 738-743 ◽  
Author(s):  
N Harris ◽  
V Galpchian ◽  
N Rifai
Keyword(s):  
High Density Lipoprotein ◽  
High Density Lipoprotein Cholesterol ◽  
Dextran Sulfate ◽  
Direct Method ◽  
Density Lipoprotein ◽  
Reference Method ◽  
High Density ◽  
Lipoprotein Cholesterol ◽  
Direct Assay ◽  
Wide Range

Abstract We compared the performance of three methods for quantifying high-density lipoprotein cholesterol (HDL-C) with the Reference Method for HDL-C, using samples with a wide range of triglyceride (TG) concentrations (290-18000 mg/L). All three comparison assays-- utilizing a magnetic dextran sulfate precipitating reagent, a direct method, and a standard MgCl2-dextran sulfate reagent--were precise, with a run-to-run CV of less than or equal to 4.1%. However, the systematic error of these assays exceeded the National Cholesterol Education Program (NCEP) performance goal of less than or equal to 10% in half of the concentration ranges tested. Nevertheless, the total error of the assays generally meets the current 22% limit set by the NCEP. Although both the magnetic dextran sulfate precipitation reagent and the direct assay can be performed more rapidly than the MgCl2-dextran sulfate assay, the direct assay involves no sample preparation and requires only 4 microL of sample excluding the dead space. Although precipitation is frequently inadequate with the MgCl2-dextran sulfate reagent at TG concentrations >6000 mg/L, both the magnetic and the direct reagent show no interference from high TG concentrations as great as 18 000 mg/L.

Sign in / Sign up

Export Citation Format

Share Document