Colorimetric assay for serum magnesium

Summary

Magnesium and cadmium ions in serum bind to methyl muscimol blue staining in alkaline solution, and the addition of EGTA can mask the interference of the ions. Magnesium, cadmium ions in serum bind to methyl muscimol blue staining in the middle section of alkaline solution, and the addition of EGTA can mask the interference of ions by presenting or blue-purple compounds.

Operation method

Colorimetric assay for serum magnesium

Principle

Serum magnesium, cadmium ions in alkaline solution segments bind to methyl muscimol blue staining, showing or blue-purple compounds addition of EGTA can mask the ionic interference.

Move

I. Experimental reagents:

1. Alkaline buffer: weigh anhydrous sodium sulfite 2g, sodium azide 100mg, glycine 750mg and ethylene glycol-bis-(2-aminoethyl ether) tetraacetic acid [Ethylene glycol-bis(2-aminoethyl ether)-N,N,N',N'-tetrazcetic acid abbreviation: EGTA] 90mg In a small burner, add lmol/L sodium hydroxide 23ml to dissolve, transfer to 100ml volumetric flask, add deionized water to the scale.

2. Color developer: weigh accurately methyl muscimol blue (AR) and polyvinylpyrrolidone (PVP) 0.6g in the burner, add 1mol/L hydrochloric acid solution 10ml, make it dissolve and then transferred to 100ml volumetric flask, add deionized water to the scale, mix well, and store in brown.

3. Color development application liquid: mix the above 1 liquid and 2 liquid in equal amount before use.

4. Magnesium standard solution: (2mg/dL)

Experimental operation: Take 3 dry test tubes cleaned with deionized water treated with dilute hydrochloric acid, label the standard and blank tubes, and then operate according to the table:

Mix well, use the spectrophotometer 600nm wavelength, 10mm colorimetric cup, and read the optical density value of each tube by zeroing the blank tube.

Third, calculation:

Serum magnesium mmol/L = absorbance of measurement tube/absorbance of standard tube × 0.823

Reference value: 0.67-l.04 mmol/L

Caveat

1. Hemolyzed specimen will interfere with this assay, so it should be avoided.

2. EGTA is a metal complexing agent that binds magnesium but not magnesium under alkaline conditions, but too high a concentration can also complex magnesium, so weighing must be accurate.

For more product details, please visit Aladdin Scientific website.

https://www.aladdinsci.com/