Gary Firth

Penetration of oral and topical ciprofloxacin into the aqueous humour

Aims: To investigate the penetration of ciprofloxacin via different modes of administration into the aqueous humour using capillary zone electrophoresis and to determine its prophylactic role in ophthalmic surgery.

Antibody-coated liposomes as a particulate solid phase for immunoassays : measurement of urinary micro-albumin

A novel use of liposomes as a solid phase material achieving separation in immunoassays is described. Antibody-coated liposomes were prepared and used as a particulate solid phase in a radioimmunoassay procedure for urinary albumin. The assay was compared to a liquid phase albumin radioimmunoassay. The potential benefits of liposomes over other particulate solid phases are discussed. The use of liposomes in this manner need not be restricted to radioimmunoassay but should also be applicable to other immunoassays using alternative non-isotopic labels.

Isoelectric Focusing in an Immobilized pH Gradient for the Detection of Intrathecal IgG in Cerebrospinal Fluid: Sensitivity and Specificity for the Diagnosis of Multiple Sclerosis

Cerebrospinal fluid and serum from 192 patients was analysed for the presence of intrathecally synthesized oligoclonal IgG bands using isoelectric focusing in an immobilized pH gradient pH7–10. The sensitivity of this method for the diagnosis of multiple sclerosis (MS) was 95% (21 of 22), or 75% if patients with suspected MS were included. The specificity for the diagnosis of MS was 98%, or 96% if the suspected MS patients were included. The very high specificity may be because the intrathecally synthesized oligoclonal IgG associated with MS is more alkaline than IgG from serum and is better detected in an immobilized alkaline pH gradient.

A NOVEL COLOURIMETRIC HOMOGENEOUS LIPOSOMAL IMMUNOASSAY USING SULPHORHODAMINE B

The dye, Sulphorhodamine B, was entrapped within liposomes prepared by the reverse evaporation technique. Marked differences in absorption spectra were found when free and entrapped dyes were compared, with a shift in the wavelength of maximum absorption. When entrapped dye was released by lysis of the liposomes, for example by detergent, the absorption spectrum reverted to that of free dye. This absorption change was employed in a novel marker system for complement-mediated immunoassay. As a model assay, human serum albumin was measured using this approach. Liposomes which had been coated with albumin were incubated with anti-albumin antibody and complement and the resulting absorption change measured using an automated spectrophotometric analyser. The decrease in absorption change on the addition of albumin formed the basis of a competitive homogeneous immunoassay for human serum albumin. Using purified albumin as a standard, a correlation of 0.96 was obtained when the albumin in human serum was measured in the liposomal assay and the results compared to measurements using a bromocresol green method.

A year's experience of the Roche Advantage II glucose test strip

The findings of a ward-based quality assurance scheme for near-patient blood glucose measurement have been analysed statistically. They provide evidence to support an improved analytical performance of a new glucose meter test strip, the Advantage II test strip, which has been in use in our hospital for over a year.

Electrophoresis of cerebrospinal fluid.

Under normal circumstances, cerebrospinal fluid (CSF) is a clear and colorless fluid that is formed in the ventricles of the brain. It is in close proximity to the surface of both the brain and spinal cord, and, as a result, the analysis of CSF proteins and other constituents in samples taken by lumbar puncture have long been used as an aid in the diagnosis of neurological disorders. Various electrophoretic methods have been used, including agar gel (1), polyacrylamide (2), two-dimensional (3), and isoelectric focusing (4), with the aim of detecting profiles that are diagnostic, especially in the case of proteins. These techniques have been labor-intensive, time-consuming, and, at best, only semiquantitative. This chapter describes how the technique of capillary electrophoresis (CE) in free solution (FSCE) can be used to provide a very fast, sensitive, and reproducible method for the analysis of CSF constituents, using only nanoliter volumes of sample (5). Furthermore, on line detection of the separated constituents, using UV absorption, allows accurate quantitation.

Clinical Biochemistry Automation a Report from a UK District General Hospital

We describe the planning, selection and implementation of an advanced clinical analysis automated system into a United Kingdom National Health Service District General Hospital.