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Cited in 0 peer-reviewed publications across chromatography, organic synthesis, and cross-coupling reactions.
Soil catalase (S-CAT) primarily originates from soil microorganisms and plant root exudates. It is an important enzyme in soil metabolic processes, whose main function is to detoxify hydrogen peroxide in the soil, playing a crucial role in the reactive oxygen species scavenging system.
Assay Principle
H₂O₂ has a characteristic absorption peak at 240 nm. Soil catalase decomposes H₂O₂, causing the absorbance of the reaction solution at 240 nm to decrease over time. The rate of change in absorbance is used to represent the activity of soil catalase.
| S1505477 | Component | 48T | 96T | Storage |
| S1505477A | Reagent Ⅰ | 350 μL | 700 μL | 2-8℃ |
| S1505477B | Reagent Ⅱ | 1EA | 1EA | 2-8℃ |
| S1505477C | Reagent Ⅲ | 3 mL | 6 mL | 2-8℃ |
Note: It is recommended to perform a pilot experiment with 2-3 samples expected to have significant differences before formal testing.
Required Materials Not Provided
1. Microplate reader or UV spectrophotometer (capable of measuring absorbance at 240 nm)
2. 96-well UV plate or micro quartz cuvettes, adjustable pipettes and tips
3. Constant temperature water bath, incubator shaker, benchtop centrifuge, 30-50 mesh sieve
4. Deionized water
Experimental Procedure
1. Reagent Preparation
| Reagent Name | Preparation Steps | Notes & Storage |
| Reagent Ⅰ | Reconstitute before use: Add 34.65 mL (48T) or 69.3 mL (96T) deionized water. Mix thoroughly. | Stable at 4°C for 1 week. |
| Reagent Ⅱ | Reconstitute before use: Add 1.2 mL (48T) or 2.4 mL (96T) deionized water. Dissolve completely. | Stable at 4°C for 4 weeks. If crystals form, dissolve in a 60-90°C water bath before use. |
| Reagent Ⅲ | Ready-to-use; equilibrate to room temperature before use. | Store at 4°C. |
2. Sample Preparation
Soil Sample: Air-dry fresh soil samples naturally or in a 37°C oven. Pass through a 30-50 mesh sieve.
Note: Fresh samples are recommended. If not used immediately, samples can be stored at -80°C for several weeks. Control thawing temperature and time during assay (if frozen). If thawing at room temperature, complete within 4 hours.
3. Assay Procedure
3.1 Instrument Preparation
Preheat the microplate reader or UV spectrophotometer for 30 minutes. Set the wavelength to 240 nm.
Zero the UV spectrophotometer with deionized water.
3.2 Assay Setup (Perform in 1.5 mL EP tubes)
| Reagent | Test Tube | No-Substrate Control Tube | No-Soil Control Tube |
| Air-dried Soil (g) | 0.03 | 0.03 | 0 |
| Reagent Ⅰ (μL) | 260 | 0 | 260 |
| Deionized Water (μL) | 0 | 260 | 0 |
Incubate at 25°C with shaking for 20 minutes.
| Reagent Ⅱ (μL) | 10 | 10 | 10 |
Mix well, centrifuge at 8,000 g, 25°C for 5 min. Transfer 180 μL supernatant to a 96-well UV plate or micro quartz cuvette.
| Reagent Ⅲ (μL) | 20 | 20 | 20 |
3.3 Measurement
Mix thoroughly and measure the absorbance at 240 nm for each tube.
Record the values as ATest, ANo-Substrate, and ANo-Soil.
Note: The No-Soil Control tube only needs to be measured once. Each Test tube requires a corresponding No-Substrate Control tube.
A pilot experiment with 2-3 variable samples is recommended before the formal assay.
If (ANo-Soil - ATest) is less than 0.01, consider increasing the sample amount.
If (ANo-Soil - ATest) is greater than 1.5, reduce the sample amount used for extraction.
4. Calculation of Results
Note: The following derived and simplified formulas are equivalent. The simplified formula (in bold) is recommended as the final calculation method.
Definition of Unit: One unit of enzyme activity is defined as the amount of enzyme that catalyzes the degradation of 1 μmol of H₂O₂ per day per gram of air-dried soil.
4.1 Calculation using a 96-well UV Plate:
S-CAT (U/g soil) = 33 × (ANo-Soil - ATest + ANo-Substrate)
Parameter Definitions:
Vtotal: Total reaction system volume, 3 × 10⁻⁴ L
ε: Molar extinction coefficient of H₂O₂, 4.36 × 10⁴ L/mol/cm
d: Light path of the 96-well UV plate, 0.5 cm
T: Reaction time, 20 min = 1/72 day
W: Sample mass, 0.03 g
4.2 Calculation using a Micro Quartz Cuvette:
S-CAT (U/g soil) = 16.5 × (ANo-Soil - ATest + ANo-Substrate)
Parameter Definitions:
Vtotal: Total reaction system volume, 3 × 10⁻⁴ L
ε: Molar extinction coefficient of H₂O₂, 4.36 × 10⁴ L/mol/cm
d: Light path of the cuvette, 1 cm
T: Reaction time, 20 min = 1/72 day
W: Sample mass, 0.03 g
5. Results Presentation

Figure 1: Typical results showing soil catalase activity measured with this kit
Precautions
1. It is recommended to perform a pilot experiment with 2-3 samples expected to have significant differences before formal testing.
2. This product is for research use only. Not for use in diagnostic procedures. For your safety and health, please wear lab coats and disposable gloves during operation.
Comprehensive hazard, handling, storage, and regulatory compliance document.
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