The visual examination of the taken liquid is a first main indication for the pathologist or the physician. The aspect of the liquid, in addition, conditions the analytical assumption of responsibility that follow and the validity of the end-results.
Microscopic analysis is an important activity of the pathologist and the laboratory assistant. They have many different colourings at their disposal (GRAM, MGG, Grocott, Ziehl-Neelsen, …). Immunofluorescence, cytochemistry, the immunocytochemistry and FISH are also used in order make a correct diagnosis.
This stage allows the pathologist to determine the character of the liquid: “normal”, tumoral, and inflammatory even infectious. Indeed, microscopic examination can often determine the causal infectious agent, in general a bacterium, a mould, a yeast, or a parasite, more rarely a virus.
The analysers, by the association of robotics and spectrophotometry, allowed these last decades a better reproducibility of the results of proportionings, in particular in medical biochemistry and hematology.
The companies of in vitro diagnosis henceforth try to sell chains of automats, i.e. a system allowing the automatic transfer of the tubes towards the various types of automats of the same mark. These systems can include the computer-assisted management of a serum library.
These analysers must undergo daily controls to guarantee a result just possible, one speaks about quality control. These analysers must also undergo daily, weekly and monthly maintenances.
A big part of the examinations of clinical pathology, primarily in medical microbiology, use culture media. Those allow, for example, the description of one or several infectious agents responsible of the clinical signs.
Values known as “normal” or reference values