Two main groups: chemistry and immunoassay
Most kits fall into two groups. Chemistry reagents are tests that run by photometric methods on serum, plasma or urine. Immunoassay kits, for example the Elecsys series, measure substances at low concentration such as hormones and cardiac markers. According to Roche package inserts, Elecsys tests are described as electrochemiluminescence immunoassay (ECLIA) used on cobas e analyzers.
Parameters measured by chemistry kits
CRP shows the level of inflammation in the body. A high value can be seen in conditions ranging from infection to autoimmune disease; it therefore does not establish a diagnosis on its own. HbA1c reflects average blood glucose over the previous two to three months; according to MedlinePlus, the test is used in screening for and diagnosing diabetes. Albumin contributes to the assessment of general health and nutritional status and of liver and kidney function.
Iron tests examine the level of iron in the body. Triglycerides are mostly requested as part of the lipid profile and are used in assessing the risk of heart and vascular disease. Lactate is most often requested to determine the presence and severity of lactic acidosis; it does not show the cause. D-dimer is used in assessing the likelihood of a clot, and the result often guides additional tests.
There are two measurements for calcium. Total calcium shows all the calcium in the blood, and ionized calcium shows only the free portion. The total calcium test is more common and is usually part of the basic or comprehensive metabolic panel.
Immunoassay kits
Ferritin shows the iron the body has stored and helps distinguish iron deficiency anemia from iron overload. Troponin is most often requested in the emergency department to confirm a heart attack. Prolactin is used when investigating the cause of complaints such as irregular periods and infertility, and in monitoring prolactinoma. Product pages are also available for Elecsys tests such as FT4, estradiol, PTH and proBNP: FT4, estradiol, PTH and proBNP.
Checklist before selection
- The analyzer on which the kit runs. Compatibility is stated in the manufacturer's product information.
- The defined sample type: serum, plasma, urine or whole blood.
- Whether calibrator and control material are required separately.
- Whether shelf life and in-use stability after opening suit the laboratory's consumption.
- The ÜTS registration of the product.
Instruments are on the test devices page. For price and supply information, the contact page can be used.
Frequently asked questions
According to Roche package inserts, Elecsys tests are used on cobas e immunoassay analyzers. Which test runs on which model is stated in the relevant package insert.
According to MedlinePlus, HbA1c gives the average blood glucose level over the previous two to three months. It is used in screening for and diagnosing diabetes.
Total and ionized calcium are not the same measurement. Total calcium measures the sum of bound and free calcium in the blood, and ionized calcium measures only the free portion. According to MedlinePlus, the two are normally present in roughly equal amounts.
Sources
- FDA, Elecsys Anti-SARS-CoV-2 package insert (ECLIA method description)
- MedlinePlus, C-Reactive Protein (CRP) Test
- MedlinePlus, Hemoglobin A1C (HbA1c) Test
- MedlinePlus, Albumin Blood Test
- MedlinePlus, Iron Tests
- MedlinePlus, Triglycerides Test
- MedlinePlus, Lactate Test
- MedlinePlus, D-dimer Test
- MedlinePlus, Calcium Blood Test
- MedlinePlus, Ferritin Blood Test
- MedlinePlus, Troponin Test
- MedlinePlus, Prolactin Levels
- MedlinePlus, Comprehensive Metabolic Panel (CMP)
- Roche Diagnostics, cobas c 111 analyzer