What is the method for detecting plasma protamine

The detection of plasma protamine is mainly accomplished through five methods: laboratory immunoassay, high-performance liquid chromatography, electrochemiluminescence, enzyme-linked immunosorbent assay, and mass spectrometry analysis. The test results are used to evaluate the neutralizing effect of heparin, assist in diagnosing coagulation abnormalities, and monitor postoperative anticoagulant therapy.

1. Immunoassay method:

uses the principle of specific antibody binding to fish sperm protein, and quantitatively detects through turbidity or fluorescence labeling. This method is easy to operate and suitable for routine laboratory testing, with a detectable concentration range of 0.1-10 μ g/ml. However, it may be affected by interfering substances such as rheumatoid factor.

2. High performance liquid chromatography:

uses a reverse phase chromatography column to separate protamine from plasma, and quantifies it at a wavelength of 220nm using a UV detector. This method has a sensitivity of 0.05 μ g/ml and can distinguish different subtypes of protamine, but it requires specialized equipment and is time-consuming.

3. Electrochemiluminescence:

is based on the tri pyridine ruthenium labeling technology, which generates a light signal through electrical excitation for detection. The detection limit can reach 0.01 μ g/ml, with a wide linear range, suitable for batch sample detection, but the reagent cost is relatively high.

4. Enzyme linked immunosorbent assay:

The fish sperm protein antibody is coated on a microplate and quantified by enzyme-linked immunosorbent assay. Routine testing takes 2-3 hours to complete, suitable for small and medium-sized laboratories, but there is a risk of cross reactivity and blank controls need to be set up.

5. Mass spectrometry analysis method:

uses liquid chromatography tandem mass spectrometry technology to qualitatively and quantitatively analyze characteristic ion fragments. This method has the strongest specificity and can simultaneously detect multiple modified forms of protamine, but it requires a high-resolution mass spectrometer and professional operators.

Fasting for 8 hours before testing is required to avoid lipid interference, and sodium citrate anticoagulant tubes should be used for blood collection. Heparin treatment patients should take samples 2 hours after administration, which should be stored at 4 ℃ and tested within 6 hours. Long term monitors recommend fixed testing methods and time periods, and taking a 30 minute break after vigorous exercise before blood collection. When the results are abnormal, a comprehensive judgment should be made based on indicators such as activated clotting time and anti Xa factor activity. If necessary, repeated testing should be conducted to eliminate experimental errors.