Diagnostic Laboratory Equipment
The Growing Variety and Uses of Diagnostic Lab Equipment
Not only was the range of diagnostic tests more limited in the past than today but the type of lab equipment now used has also undergone impressive changes. The days of diluting a drop of blood and comparing it visually with a colour chart to approximate the percentage of haemoglobin present are now long gone, to be replaced by more accurate methods employing spectrophotometry. In addition, there are now procedures for the detection and quantitation of biological elements that were either previously unknown or for which no suitable assay techniques were available.
Much of today’s biomedical technology revolves around the development of methods that are not only accurate but that can produce results as quickly as possible. Such techniques employ diagnostic reagents and equipment developed with these attributes in mind and will often serve as a rapid screening procedure that may be conducted in a lab, a mobile clinic at a patient’s bedside or, in some cases, even at home.
When it is required to perform large numbers of analyses, instrument manufacturers have responded with a steady supply of increasingly sophisticated automated systems. While initially limited to single biochemical tests or the preparation of tissue samples for microscopy, the systems in use today have opened up many new and valuable possibilities. These include machines capable of simultaneously assaying multiple chemical components in body fluids, of determining blood groups, of identifying and counting the immature forms of red cells, white cells and platelets present in blood and even the inoculation of culture plates. Clearly, the two latter applications serve to dispel any illusion that the disciplines of haematology and microbiology are destined to remain strictly in the domain of the human operative.
Among the diagnostic lab procedures now used widely, ELISA employs specialised equipment to house the samples and reagents, and to measure the colour produced by the reaction. An acronym for Enzyme-Linked, Immunosorbent Assay, the compounds, commonly antibodies or antigens, to be analysed within the sample are first adsorbed on to a stationary solid. This is then treated sequentially with various reagents and incubated, to produce a coloured end-product of an intensity proportionate to the concentration of the component under assay, which is then quantified using a specially designed spectrophotometer.
The applications for ELISA technology are numerous and new ones are being added on a regular basis. For instance, it is a highly effective tool for the detection of virus infections such as Ebola, West Nile Virus, Influenza and HIV. It may also be used to screen for bacterial infections such as Lyme Disease and Rocky Mountain Spotted Fever, or parasitic infections including Malaria and Leishmaniasis. Though rather less complex than most diagnostic lab equipment, home pregnancy kits also make use of an ELISA variant to detect human chorionic gonadotrophin.
The food industry, however, is now equally reliant on this technology both for bacterial testing and for the detection of potential allergens in their products. These include milk, eggs, shellfish, wheat, soy, tree nuts and ground nuts and it is now a legal requirement for producers to label their products accordingly.
Analysis, whether for medical or commercial purposes, is a complex field. In South Africa, nobody understands it better than IEPSA, so consult us for all your diagnostic lab equipment needs.
