Osmotic Fragility Test

Osmotic fragility refers to the tendency of materials to break down or fail under stress when subjected to changes in pressure. When a material is exposed to high levels of heat, it will begin breaking down at a faster rate than other materials. These types of substances are called thermoplastics and include polymers such as Styrofoam and plastic food containers like Tupperware. Osmotic fragility tests have been used since the 1970’s by scientists studying these materials. They are designed to determine if the materials can withstand the stresses of being placed under extreme conditions.

The osmotic fragility test involves placing a sample of a material under varying amounts of pressure and then monitoring how much time it takes for the sample to degrade. If there is any change in the amount of time required for degradation, it means that the material has failed under stress.

A number of different methods exist for conducting the test. Some of them include:

1) Pressure Drop Test – This method uses a drop of liquid containing the substance under consideration into a container with no air pockets.

After some time passes, the container must be opened to check whether or not the substance has broken down.

2) Overpressure Test – In this test, the pressure is increased over time until the material fails.

One variation of this method involves placing a sample and a control sample side by side and then slowly increasing the amount of pressure over time. If at any point in time the sample has broken down and the control has not, then the sample has failed the test.

3) Multiple Staged Osmotic Fragility Test – In this test, the sample is slowly raised to a specific temperature and then subjected to a range of differential pressures.

If the material breaks down during any part of the test, it is considered that the material fails the osmotic fragility test.

The Osmotic Fragility Test is used on a daily basis to test for the degradation of multiple materials and substances. It is important to know whether or not a material will break down under widely varying conditions so that products can be designed to effectively last a long time.

VN:F [1.9.22_1171]

please wait…

Rating: 6.8/10 (9 votes cast)

VN:F [1.9.22_1171]

Rating: +3 (from 5 votes)

Sources & references used in this article:

Screening for beta-thalassaemia carriers in Egypt: significance of the osmotic fragility test by A El Beshlawy, N Kaddah, A Moustafa… – … Health Journal, 13 (4) …, 2007 – apps.who.int

Erythrocyte osmotic fragility test for screening of alpha-thalassemia-1 and beta-thalassemia trait in pregnancy by S Sirichotiyakul, C Tantipalakorn… – International Journal of …, 2004 – Elsevier

… hereditary spherocytosis using five laboratory tests (cryohemolysis test, eosin-5′-maleimide flow cytometry, osmotic fragility test, autohemolysis test, and SDS-PAGE) … by RL Crisp, L Solari, D Vota, E García, G Miguez… – Annals of …, 2011 – Springer

Comparison of acidified glycerol lysis test, Pink test and osmotic fragility test in hereditary spherocytosis: effect of incubation by MJL Bucx, WPM Breed… – European journal of …, 1988 – Wiley Online Library

Erythrocyte osmotic fragility test as the measure of defence against free radicals in rabbits of different age by E Brzezińska-Ślebodzińska – Acta Veterinaria Hungarica, 2001 – akjournals.com

A new method of osmotic fragility test of erythrocytes with coil planet centrifuge by R Harada, Y ITO, E KIMURA – The Japanese journal of physiology, 1969 – jstage.jst.go.jp