ABSTRACT
The effects of acoustic microstreaming during incubation steps of a prototypical three-step ELISA were studied. Acoustic microstreaming, an orderly mixing of microwell contents induced by linear oscillation of immersible acoustic probes, was shown to be particularly effective when coupled with locating the solid phase on the surface of the probes. Optical densities achieved for acoustic probe-based assays were equivalent to those for uninsonated microwell-based assays with only 20% of the microwell solid phase surface area. Low-level antibody detection was significantly improved and antibody incubation times significantly shortened without loss of signal. Acoustic probe-based assays can enhance assay and laboratory efficiency through testing for multiple analytes in a single sample or increasing available binding surface area (by using probe and well surfaces simultaneously), and by eliminating quenching. Acoustic probe ELISA methodology has significant implications for cost-effective automation.
Subject(s)
Acoustics , Enzyme-Linked Immunosorbent Assay/methods , Animals , Immunoglobulin G/analysisABSTRACT
To test the hypothesis that liver function is different in populations with inherited susceptibility to persistent Australia antigen (hepatitis B surface antigen [HBsAg]), Sardinians living in Turin, Italy, were compared with their native Turinese neighbors. The study was controlled for age, sex, place of birth, and presence or absence of persistent HBsAg. Slight differences in liver function were found in the Sardinians compared with the Turinese. Their values were in the direction of abnormality. Sardinians also had considerably higher serum gamma-globulin levels than the Turinese. The levels of alpha2-globulin by electrophoresis correlated with the presence of HBsAg.
Subject(s)
Hepatitis B Antigens , Liver/physiopathology , Alanine Transaminase/blood , Alpha-Globulins/analysis , Aspartate Aminotransferases/blood , Bilirubin/blood , Humans , Italy/ethnology , Liver Function Tests , Nephelometry and Turbidimetry , Serum Albumin/blood , Thymol , gamma-Globulins/analysisABSTRACT
Purified and concentrated preparations of Australia antigen had no stimulating effect on leukocytes of human subjects under study when tested either on DNA-polymerase activity, 3H-thymidine uptake or chromosomal alterations. Moreover, in patients with chronic hepatitis and cirrhosis of the liver no correlation between antigenemia and chromosome aberrations in blood leukocyte cultures could be detected. On the other hand, a serum obtained from a virus hepatitis patient with Australia antigen in the blood was found to stimulate leukocyte cultures from one patient with Down's syndrome and antigenemia, one mentally retarded patient and three normal donors. This stimulating agent is obviously not associated with Australia antigen.
