A method of measuring glycosylated hemoglobin featuring, in one aspect, providing a sample containing hemoglobin, including an unknown amount of glycosylated hemoglobin, contacting the sample with an oxidizing agent to generate formaldehyde, and measuring the formaldehyde as a measure of glycosylated hemoglobin, the measuring being carried out by reacting the formaldehyde with a water-soluble amine or an ammonium salt and a .beta.-diketone to generate a fluorescent compound whose fluorescence is measured as a measure of glycosylated hemoglobin.
Methods and apparatus for monitoring formaldehyde vapor in a gas, comprising directing the gas into contact with an aqueous acidic solution that can dissolve the vapor and thus collect it therein, separating the gas from the solution, reacting the solution with a reagent to form from the collected formaldehyde a derivative that can be excited by radiation at a wavelength in the range of about 230 to 300 (typically 254) nanometers to fluoresce at a substantially different wavelength, irradiating the solution at a wavelength in said range for excitation, and measuring the intensity of the resulting fluorescence. Typically the fluorescence is measured at a wavelength in the range of about 450 to 550 nanometers and the irradiation and the measurement of fluorescence are carried out by means comprising conventional fluorometric means.
A composition, device and method for preparing a ketone control solution are disclosed. The composition comprises dimethylformamide and a Group I, II or III metal salt of a .beta.-keto acid ester. The salt has the structure ##STR1## in which R is lower alkyl of 1 to 6 carbon atoms, R' is an aliphatic or cyclic group having 1 to about 7 carbon atoms, M is a Group I, II or III metal ion and n is 1, 2 or 3. A carrier matrix incorporated with the composition can be affixed to a support member to form the device. Preferably, a hydrolyzing agent is included on the device in the same or another carrier matrix. The method for preparing the control solution comprises contacting a predetermined volume of an aqueous solution with the device for a predetermined time.
Methods and apparatus for separating red blood cells by density are described. Older red blood cells are more dense than younger ones. Certain changes in the physiology are recorded in changes in hemoglobin or the red blood cells. By assaying different aged red blood cells, one can determine the historical physiological changes over a period of many weeks. Improved separation of red blood cells is accomplished by using rigid capillary tubes having an inner surface which augments the density equilibrium of red blood cells and/or incrementally increasing the centrifugation forces, as well as by chemically treating red blood cells to improve their deformability.
An immunoassay for a protein that is non-enzymatically glycosylated on the alpha amino group of its N-terminal amino acid, the immunoassay comprising: providing a sample containing the glycosylated protein; reacting the glycosylated protein with a reducing agent so that the sugar residue on the N-terminal amino acid is reduced; contacting the reduced glycosylated protein with an antibody directed to Glc-ol-X which is prepared by immunizing an animal with an immunogen of the formula (Glc-ol-X-L).sub.n -carrier; and detecting or quantitating the reduced glycosylated protein bound to the antibody. In the formula (Glc-ol-X-L).sub.n -carrier: X is the N-terminal amino acid of the glycosylated protein, except that X cannot be lysine; L is a bond or a linker group; Glc-ol is the reduced form of the sugar attached to X on the glycosylated protein, and Glc-ol is attached to the alpha amino group of X; the carrier is an immunogenic compound other than the glycosylated protein; and n is from 1 to the number of available coupling sites on the carrier. Also, the antibody, the immunogen, and methods of making them. Finally, a kit for quantitating a protein glycosylated on its N-terminal amino acid.
