摘要:
A device which can be used for filtering samples is described. The device is comprised of a plurality of filter wells, each having a wide region and a narrow region. The device is fitted with a filter element and then filled with a gel filtration matrix which is selected so that molecules of a particular molecular size will diffuse into the matrix. The device is centrifuged to remove water from the interstitial regions of the gel filtration matrix, and a sample is then added to the device containing the dried gel filtration matrix. The device is again centrifuged, causing smaller molecules to diffuse into the matrix and allowing larger molecules to exit the device, wherein they are collected and analyzed. The device is capable of filtering sample sizes as low as 1 &mgr;L and can be used in a variety of existing laboratory equipment, including bench-top centrifuges and microcentrifuges. A process for using the device is also disclosed.
摘要:
A method for detecting the presence of cystic fibrosis ciliostatic factor in mammalian body fluid comprisescontacting an enzyme whose activity is inhibited by the factor with a substrate for the enzyme in the presence of the body fluid, the substrate being substantially resistant to reactions catalyzed by enzymes in the body fluid, whereby the substrate is converted by the enzyme at a measurable rate, andcomparing the rate of substrate conversion with the rate of substrate conversion by the enzyme in the absence of cystic fibrosis ciliostatic factor.
摘要:
A maltodextrin phosphorylase limit dextrin in the presence of maltodextrin phosphorylase and inorganic phosphate, is used as a substrate for alpha-amylase, which initiates a series of enzymatic reactions resulting in a chromogen response which can be used to measure the concentration of alpha-amylase in a body fluid. A novel limit dextrin and its preparation also are described.
摘要:
A maltodextrin phosphorylase limit dextrin in the presence of maltodextrin phosphorylase and inorganic phosphate, is used as a substrate for alpha-amylase, which initiates a series of enzymatic reactions resulting in a chromogen response which can be used to measure the concentration of alpha-amylase in a body fluid. A novel limit dextrin and its preparation also are described.
摘要:
A new stable combination of Rhizopus arrhizus lipase and Pseudomonas fluorescens lipase for hydrolyzing triglycerides to free glycerol in body fluids is disclosed. Substantially complete and rapid hydrolysis is provided by a mixture of enzymes using a ratio between 2:1 and 10:1, about 5:1 being preferred, the amounts representing units of activity of each lipase. Approximately 150 units of total lipases will provide substantially complete hydrolysis of the triglycerides contained in 20 microliters of serum up to a minimum concentration of 5 g./l. within 2.5 minutes at 37.degree. C.
摘要:
A 3-aminobenzoic acid or a 3-aminobenzenesulfonic acid, when reacted with a 4-aminoantipyrine in aqueous medium in the presence of hydrogen peroxide forms a novel colored dye which is believed to be a charge-transfer complex of free radicals formed from the 3-aminoaromatic acid and the 4-aminoantipyrine. The dye and the process by which it is produced are useful in analytical procedures for hydrogen peroxide, as well as in enzymatic analyses involving the formation of hydrogen peroxide.
摘要:
A 3-aminobenzoic acid or a 3-aminobenzenesulfonic acid, when reacted with a 4-aminoantipyrine in aqueous medium in the presence of hydrogen peroxide forms a novel colored dye which is believed to be a charge-transfer complex of free radicals formed from the 3-aminoaromatic acid and the 4-aminoantipyrine. The dye and the process by which it is produced are useful in analytical procedures for hydrogen peroxide, as well as in enzymatic analyses involving the formation of hydrogen peroxide.