Medical Lab Investigations For Dummies

Medical Lab Investigations For Dummies 
Medical lab investigation must be a part of everyone medical information knowledge.

Almost all of us have done at least one lab test in lifetime, but what do we know about what happens behind lab door? All lab investigations need sterilized clean area, so the first thing you have to know is that; limited access to what behind the doors is a must. Lab tests are investigation methods that can form the final decision of the physician, so requires a great deal of accuracy.
Lab investigations are divided into three major groups according to the nature of the test itself:-
1- Chemical.
2- Microbiological.

3- Histopathologic.

The first group which is the chemical group, (in my opinion) it is the easiest and less technical one. It depends upon simple chemical reactions that may produce chemical compounds with distinctive characters like distinctive color, odor or distinctive physical property (solubility as an example), so this distinctive character can be detected and gives a positive result.

Examples for this category are so popular and widely used like, (blood sugar sets, pregnancy test kits, hepatic viruses C, B, A and H.I.V detecting kits, urine analysis for (ca oxalates, keton bodies, albumin urea)). It may include the involvement of qualitative*, quantitative* and spectrophotometeric* analysis.
Procedure
Fresh sample is been mixed with certain reagent in a reaction which produces certain compound that can be identified by its physical properties and/or its quantity can be measured by the intensity of this physical properties.

The second group which is the microbiological one (in my opinion) requires much more experience and technician skills than all the other methods; it requires complete sterilization and warm environment.
All the bacterial and viral cultures for antibiotic effectiveness are belonging to this group.
It’s also pretty obvious that this group is the most dangerous and workers’ health hazardous of all the other lab test groups. Protozoa infection tests also belong to this group, most of the lab procedures of that group are done using dyes and investigation under the microscope.



Procedure
Fresh life sample is been taken from the patient in the lab (sputum, urine, blood, stool or lesion secretion) and preserved in nutrition rich media then prepared for investigation.

The third group which is the Histopathologic group is concerned with tissue and cell/cell components analysis. This group although it isn’t the most technical group, but it requires a great deal of academic knowledge, most of the lab procedure of this group are also done using dyes and investigation under the microscope.
This group main aim is to identify the effect of the disease on normal tissue structure and behavior. Most tumors and malignances are diagnoses using this type of lab investigations.
Procedure
Sample is been collected by skilled physician (mostly surgeon) and packed properly in ice to be send to the lab for Histopathologic investigation.

Quantitative analysis:lab investigation methods to evaluate the quantity of the certain element or compound.
Qualitative analysis: lab investigation methods aim to identify the type of unknown element or compound.
Spectrophotometeric analysis: lab investigation methods aim to identify either the type and/or the quantity of known/ unknown element by its color and optical properties.