Clinical Chemistry - DP analyzer

Hey, here's Natasha:]

I am attached to a clinical chemistry lab for my SIP. There are a number of workstations consisting of different analyzers in this clinical chemistry lab. For the first week, I am assigned to the Modular Analytics Evo DP analyzer.

This DP analyzer can be divided into three sections; D module, P module and ISE module.

The D and P modules of the DP analyzer actually performs photometric assays on serum/plasma, urine and CSF samples. It measures the absorbancies of the chemical reaction in the reaction cells when the sample is mixed with the appropriate reagent. The D module performs several tests such as renal function test (urea, creatinine, etc), liver function test (AST, ALP, etc) and lipids (total cholesterol, triglycerides, etc). The P module can actually perform tests similar to the D module; however in this clinical lab, it is used to conduct the diabetic panel test (glucose) only. The only difference between the D and P modules is the method used to add the reagents into the reaction cells. The D module stands for 'dispensing' so it will dispense the reagents into the reaction cells. The P module stands for ' pipetting' so it will pipette the reagent from the reagent bottle and then release it into the reaction cells.

The ISE module, however, invloves measuring the difference in electircal potential between the sample measurement electrode and the reference electrode. The electrical poential of the KCl reference solution on the reference electrode serves as a zero baseline for the ISE calculations of the samples. The ISE module is used to determine the amount of sodium, potassium and chloride in the samples.

One of the tests that could be performed on the DP analyzer (specfically P module) is the glucose tolerance test (GTT). GTT is actually the dministration of glucose to determine how quickly glucose is cleared from the bood of the patient. The test is usually used to test for diabetes and insulin resistance in those patients.

Glucose is the major monosaccharides present in the blood and serves as an esential energy supplying substrate for cellular functions Glucose degradation occurs via glycolysis. Glucose determinations can be used in detecting hypoglycaemia and hyperglycaemia, in the diagnosis of diabetes as well as in the monitoring of glucose levels in people with diabetes.

The patient sample is taken in the form of blood in sodium fluoride/ potassium oxalate tubes (grey tubes). Sodium fluoride is an anti-glycolytic agent which aids in inhibitng glycolysis. The patient would have to fast the night before the test. For the test, the patient would have to drink a liquid containing a certain amount of glucose. Then after 2 hours, the patient's blood will betaken again. Thus there will be two grey tubes; one containing patient blood at 0 hours before the intake of glucose drink and the other containing patient blood at 2 hours after the intake of glucose drink.

In a person without diabetes, the glucose levels will rise and then fall rapidly. However in a person with diabetes, glucose levels will rise higher than normal and fail to come back down as fast.