DRUG ANALYSIS

The AIDS Research Program Toxicology Laboratory is equipped with the instruments necessary for the detection of a variety of drugs including cocaine, heroin, and THC. With these instruments, laboratory personnel are able to analyze blood samples from IDU (Intravenous Drug Users) in order to determine the different drugs being used as well as the effect(s) of these drugs on the HIV virus. For carrying out these tests, we utilize a GC/MS from Agilent Technologies and the Abbott AxSYM System.

GC/MS

The mass spectrometer, in particular the Agilents GC/MS System is widely been used to detect and analyze drugs of abuse and their metabolites in body fluids.

The mass spectrometer, in particular the Agilents GC/MS System is widely been used to detect and analyze drugs of abuse and their metabolites in body fluids.

Mass spectrometers are used to separate matter according to its mass, both molecular and atomic. The ARP, in its work with drug use associated with HIV, relies heavily on this piece of equipment.

During analysis, several distinct processes occur: electron ionization and the subsequent fragmentation of molecules and the determination of the mass to charge ratio (m/z). The relative abundance of the ions that result from these processes is then measured. The detector records the abundance of each (m/z), which produces a signal. This signal is analyzed by the computer software which then generates a (TIC) “Total Ion Chromatogram” that produce a qualitative report.

Abbott AxSYM System

The Abbott AxSYM uses three different technologies to perform assays. These are the Microparticle Enzyme Immunoassay (MEIA), the Fluorescence Polarization Immunoassay (FPIA) and the Radiative Energy Attenuation.

In our lab we use the Fluorescence Polarization Immunoassay (FPIA); the FPIA reaction is as follows:

1. A Sample, Pretreatment Reagent, and Line Diluent are combined and incubated. An initial reading is taken as a blank for the assay.
2. Antibody, Tracer, Line Diluent, and more sample are added to the reaction mixture and then incubated. The analyte from the sample competes with the analyze tracer for the binding sites on the antibodies.
3. Depending on the sample concentration of analyte in the specimen, the FPIA optics detect and measure the change in polarization of emitted florescence. The fluorescence is inversely proportional to the concentration.

Right now we are in the process of upgrading our instruments. The GC/MS will receive software updates; we expect to add new assays to the Abbott AxSYM System for the detection of Hepatitis A, B, and C.

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