Magnesium (Mg) Content Assay Kit (MTB, Colorimetric Method)

Cat. No.: M1506762

GRADE & PURITY BioReagent

Descripción general

Magnesium acts as a cofactor for numerous enzymes and is present in both soft tissues and bone, with roughly equal distribution between the two. The metabolic regulation of magnesium remains incompletely understood. Elevated magnesium levels can lead to reduced muscle tone, while decreased levels are associated with conditions such as hypoparathyroidism and chronic renal failure.

Detection Principle

In an alkaline solution, magnesium ions bind with Methyl Thymol Blue (MTB) to form a blue-violet complex. The addition of a calcium ion chelator eliminates background interference from calcium ions. The absorbance of this complex is measured at 600 nm using a spectrophotometer, and the magnesium content is calculated based on a formula. This kit is intended for research use only and is not suitable for clinical diagnosis or other purposes.

M1506762	Component	100T	Storage
M1506762A	Magnesium Standard (0.823 mmol/L)	1 mL	2-8℃
M1506762B	Mg Assay Buffer	100 mL	2-8℃
M1506762C	MTB Chromogenic Solution	100 mL	2-8℃. Store in the dark.
M1506762D	ddH₂O	100 mL	RT

Materials Required but Not Provided

Centrifuge tubes or test tubes, Cuvettes, Spectrophotometer

Experimental Procedure

1. Sample Preparation

1.1 Plasma/Serum Samples

Plasma or serum samples prepared by standard methods can be used directly for assay with this kit. Store at -20°C for Mg detection.

1.2 Cell or Tissue Samples

Homogenize an appropriate amount of cells or tissue. Centrifuge at low speed to collect the supernatant. Store at -20°C for Mg detection.

1.3 High Concentration Samples

If the sample contains a high concentration of Mg, dilute with the provided ddH₂O. The use of ordinary distilled water for dilution is not recommended.

Note: After sample preparation, the protein concentration can be determined using a BCA protein assay kit to facilitate subsequent calculation of Mg content per unit protein weight in tissues or cells. The Aladdin B665595 BCA Protein Quantification Kit or R1491648 Ready-to-Use BCA Protein Quantification Kit is recommended.

2. Preparation of Mg Chromogenic Working Solution

Immediately before use, mix equal volumes of Mg Assay Buffer and MTB Chromogenic Solution. Prepare fresh for each use. If necessary, the working solution can be stored at 4°C protected from light for short periods, but prolonged storage is not recommended.

3. Mg Assay Setup

Use dry test tubes cleaned with dilute hydrochloric acid and rinsed with deionized water, or disposable sterile polyethylene centrifuge tubes. Set up Blank, Standard, and Test tubes according to the table below. Add solutions in the specified order, avoiding bubble formation. If the magnesium ion concentration in the sample is too high, reduce the sample volume or dilute appropriately before assay. Running sample duplicates is recommended.

Reagent (mL)	Blank Tube	Standard Tube	Test Tube
ddH₂O	0.2	—	—
Magnesium Standard (0.823 mmol/L)	—	0.2	—
Test Sample	—	—	0.2
Mg Chromogenic Working Solution	1.8	1.8	1.8

4. Mg Measurement

Mix well and incubate at room temperature for 5 minutes. The solution color develops from green to light blue-violet. Using the Blank tube to zero the instrument, measure the absorbance of the Standard and Test tubes at 600 nm using a cuvette with a 1 cm light path (recorded as A_standard and A_test).

5. Calculation of Results

• Serum/Plasma Magnesium:

  Magnesium (mmol/L) = (A_test / A_standard) × 0.823

• Tissue Magnesium:

  Magnesium (mmol/mg prot) = (A_test / A_standard) × 0.823 / (c × 1000)

Parameter Description:

• A_test: Absorbance of the test tube

• A_standard: Absorbance of the standard tube

• c: Protein concentration of the test sample, mg/mL

• Unit Conversion: mg/dL = mmol/L / 0.411

Reference Interval: Serum magnesium concentration in healthy adults: 0.67 ~ 1.04 mmol/L (1.64 ~ 2.52 mg/dL)

Precautions

1. Hemolyzed samples interfere with the assay; avoid using them whenever possible.

2. This method can be adapted for automated biochemical analyzers using an endpoint detection method.

3. Under the conditions of this kit, the magnesium ion concentration in the test sample should preferably be greater than 0.08 mmol/L to avoid potential detection errors.

4. The absorbance of the 0.823 mmol/L Magnesium Standard, when measured by spectrophotometer, typically falls between 0.2 and 0.4. Empirical data suggests results may deviate for sample concentrations below 0.1 mmol/L or above 1.6 mmol/L.

5. If the sample concentration is too high, dilute with ddH₂O and re-assay, multiplying the result by the dilution factor.

6. Use reagents promptly after opening to prevent potential effects on subsequent experimental results.

Almacenamiento y envío

Condiciones de almacenamiento de almacenamiento

Store at 2-8°C,Protected from light,Room temperature

Enviado en

Wet ice

Estabilidad y almacenamiento

Each component has a shelf life of 1 year under corresponding storage conditions. M1506762A, M1506762B:  Store at 2-8℃ long term (12 months). M1506762C: Store at 2-8℃ long term (12 months). Store in the dark. M1506762D: Store at room temperature long term