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

Cat. No.: M1506753

GRADE & PURITY BioReagent

Overview

Magnesium serves as a cofactor for numerous enzymes and is present in both soft tissues and bone, with roughly equal distribution between the two. The metabolic mechanisms of magnesium are not fully understood. Elevated magnesium levels can lead to reduced muscle tone, while decreased levels are observed in 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 microplate reader, 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.

M1506753	Component	100T	Storage
M1506753A	Magnesium Standard (0.823 mmol/L)	1 mL	2-8℃
M1506753B	Mg Assay Buffer	10 mL	2-8℃
M1506753C	MTB Chromogenic Solution	10 mL	2-8℃. Store in the dark.
M1506753D	ddH₂O	10 mL	RT

Materials Required but Not Provided

Centrifuge tubes or test tubes, 96-well plate, Microplate reader (or 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 ddH₂O provided in the kit. Do not use ordinary distilled water for dilution.

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 a 96-well plate cleaned with dilute hydrochloric acid and rinsed with deionized water. Set up Blank, Standard, and Test wells 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 (μL)	Blank Well	Standard Well	Test Well
ddH₂O	20	—	—
Magnesium Standard (0.823 mmol/L)	—	20	—
Test Sample	—	—	20
Mg Chromogenic Working Solution	180	180	180

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 well to zero the instrument, measure the absorbance of the Standard and Test wells at 600 nm (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 / Protein concentration of test sample (mg/L)

Parameter Description:

• A_test: Absorbance of the test well

• A_standard: Absorbance of the standard well

• 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.

Storage and Shipping

Storage

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

Shipped In

Wet ice