.png)
Dear reader, my name is Márcia Arieira, I’m 22 years old and I’m a biologist. Currently, I’m a student in a master's degree in Clinical Analysis at the University of Porto (FFUP). During the last year of my Biology degree, I had the opportunity to do an internship at a Clinical Analysis Laboratory and, after it, I decided to enter the labor world in the same area.
Clinical analysis is essential for diagnosis, prognosis and for therapeutic decisions. Over time, this area has been evolving, both in the methods and techniques used and in the equipment, as they are becoming more important in the clinical diagnosis and the follow-up of the patient's therapy.
The work at a clinical laboratory initiates with the arrival of biological samples, following triage, further submission to a range of procedures and, finally, the results validation by the technicians. The laboratory is divided into sectors: biochemistry, endocrinology, hematology, immunology, mycology, microbiology, parasitology, and urinalysis.
In order to obtain a correct diagnosis and, consequently, an adequate therapeutic, it is crucial the mitigation of laboratory errors, with health professionals being the main responsible for them, meaning that they should continuously increase the capacity of good laboratory practices. What makes possible to reduce these errors, thus facilitating their detection and localization, is the analytical process which is divided into 3 different stages – pre-analytical, analytical, and post-analytical stage.
The pre-analytical stage consists of a range of procedures performed from the first contact with the patient to an analytical phase. At this stage, after collecting information about the patient (name, age, sex, relevant clinical information and, if that is the case, known interferences), the collection of biological samples is initiated (the most frequent ones: blood, urine, faeces, expectoration (mucus), nasal exudates, purulent and vaginal and rectal exudates), leading to the manipulation, identification, conservation and transportation or, sometimes, its rejection or need to repeat the collection.
For the execution of the analytical stage it is necessary the use of analytical equipment, quantitative analytical techniques, observation techniques and internal qualitative controls.
The process of the pos-analytical stage includes the biopathological validation, examined laboratory report and its delivery, counselling to the patient, and acting on the abnormal results.
Microbiology
Microbiology is the scientific field responsible for the study of microorganisms, such as bacteria, viruses, parasites, and fungi. The main goal of clinical microbiology it is not just to find the agent causing an infectious disease but also to identify its profile, develop a clinical report and propose an adequate treatment for the patient. This is only possible when the microorganism is isolated, identified and the resistances and sensibilities to antibiotics are determined. For example, for the study of urine microbiology, this is extremely important to diagnose the infectious disease of the urinary tract.
Fig 1: Microbial isolation
Hematology
Hematology is the field that studies blood cells, hemoglobin, blood proteins, coagulation mechanisms and sedimentation rates, from whole blood collected to EDTA tubes or plasma obtained from blood collected to sodium citrate tubes. EDTA tubes are used to perform blood cell counts, sedimentation rate, evaluation of hemoglobin A1C and blood group studies. In coagulation studies and D-dimer tests, it is used plasma from sodium citrate tubes.
Fig 2: Types of blood collection tubes
Immunochemistry
The main objective of clinical biochemistry is to evaluate biochemical parameters to direct the diagnosis of numerous pathologies thus guiding and monitoring the optimal therapy for the patient. This sector is automated and analyses a high number of biochemical parameters in blood and urine samples.
References
MN Editors. (2021, December). Types of Blood Collection Tubes and Their uses. Microbiology Note. https://microbiologynote.com/types-of-blood-collection-tubes-and-their-uses/
Jibon Hridoy. (2020, October 16). General Methods of Microbial Isolation. Plantlet; Plantlet. https://plantlet.org/general-methods-of-microbial-isolation/
Comments