coag instrumentation

What kind of assay are clot-based assays, and what does this mean?

1. Functional assay

2. Goal is to see whether a clot forms

What are two methods used by clot-based assays?

1. Electromagnetic & mechanical

1. Optical

What two instruments does the electromechanical & magnetic method use?

1. Fibrometer

2. Steel ball in test

What are a Fibrometer and steel ball in test mostly used for today?

Fibrinogen assays

What are two problems with semi-automated methods (electromechanical)?

1. Pipetting

2. Cross-contamination of probes

What is the photo-optical method for clot detection?

A turbidimetric method where as the clot forms, %transmission decreases

What are three sources of error in photo-optical methods?

1. Hypercoagulability

2. Viscous plasmas that have cryo or macroglobulins

3. Increased Bilirubin, Lipemia, Hemolysis

What are chromogenic assays highly specific for?

Individual variables such as enzymes, activators, cofactors, etc

The chromosphore that creates color is called what?

para nitroanaline

The color intensity is (directly/indirectly) related the concentration of the enzyme.

Directly

What are nephelometric/immunologic methods used for? What is it based on? Is it considered a “functional assay”?

1. Quantifying an amount of a certain factor regardless of its functionality.

2. AG/AB interactions

3. No

What kinds of tests can the ACL top do?

1. Clot-based

2. Chromogenic

3. Immunologic

What kind of test does the POC I-STAT device do?

Clot-based