This method for determining aluminum in human serum involves electrothermal atomic absorption spectrophotometry. A longer drying time allows less pre-dilution of the sample, and the method also includes a flush cycle after atomization. Standard-addition methodology is used to eliminate matrix effects and the need for a standard curve. We used this method on serum from 50 normal persons and from...

Thirty clinical isolates of Staphylococcus aureus were tested for tolerance to oxacillin, cephalothin, and gentamicin by using killing curves and broth dilution susceptibility tests. Tolerance was defined as the presence of>/=100 colony-forming units per ml remaining after 24 h of incubation of the killing curve suspensions. Nineteen of 30 isolates were tolerant to oxacillin and cephalothin, bu...

We describe the use of quantitative PCR (QPCR) to titer recombinant baculoviruses. Custom primers and probe were designed to gp64 and used to calculate a standard curve of QPCR derived titers from dilutions of a previously titrated baculovirus stock. Each dilution was titrated by both plaque assay and QPCR, producing a consistent and reproducible inverse relationship between C(T) and plaque for...

The killing rate induced by ampicillin was determined in 20 strains of Escherichia coli. The apparent generation rate constant for each E. coli showed a characteristic concentration-dependent course. This course can be mathematically described and is determined by four parameters. Three of these parameters determine the speed of the process, and the fourth parameter determines a minimal concent...

A simple, relatively precise, and clinically applicable indirect method of determining relative cardiac output is presented. The principle involved is a modification of the dye-dilution principle and is performed by external monitoring of intravenously injected radioiodinated serum albumin combined with a standard detecting and recording device. This procedure was performed serially before and ...

introduction: quantification of epstein - barr virus (ebv) in peripheral blood mononuclear cells (pbmnc) of allogenic bone marrow transplant (bmt) recipients is important because ebv-associated posttransplant lymphoproliferative disease (ptld) can occur after transplantation due to immunosup-pression therapy. methods: to this end we chose real-time pcr using taqman probe. for the standard curve...

Diphtheria antitoxin antibodies were measured by solid-phase enzyme-linked immunosorbent assay (ELISA) on the basis of a calibrated antibody standard. Protective antibodies were expressed as International Units per ml (IU/ml). The method of quantitation employed is easily performed under routine conditions. Sensitivity proved to be 0.09 mIU/ml, and direct measurement of antitoxin concentrations...

A method has been developed for determination of sodium concentration (activity) in urine using a glass electrode designed to be especially sensitive to sodium ion activity. The urine is diluted 2:20 with Tris buffer (pH 8.0) and sodium activity measured by dipping a sodium electrode and calomel reference electrode in the diluted specimen and obtaining a millivolt reading with a sensitive pH me...

A method is described for measurement of human chorionic somatomammotropin (HCS) by use of a double-antibody technique, for concentrations ranging from 2 ng/ml to 20 tg/mI. The cross-reactive characteristics of rabbit anti-human HCS serum No. CT 3399 from NIAMD are explored. A dilution plan is presented utilizing a standard curve from 0.75 to 80 ng/ml. Concentrations (mean and ranges) for HCS i...

Venous blood, taken with EDTA-NaCl solution according to Schulz et al (1971, Z. Klin. Chem. Klin. Biochem. 9, 329-333) is used. The blood is centrifuged at IQOg for 10 min and 10 μΐ of the supernatant is added to 3000 μΐ of a suspending medium (dilution 1:80); 300 μΐ platelet suspension are read in a nephelometer cuvet or tube against blank. The number of platelets per liter blood are determine...