Creatinine Content Assay Kit (Deproteinization Endpoint Method)

Cat. No.: C1527215

GRADE & PURITY BioReagent, Standard Curve Method

Descripción general

Creatinine (Cr) is a metabolic product generated in the muscles of humans or animals. Approximately 1 mg of creatinine is produced from the metabolism of every 20 g muscle tissue, which is excreted via glomerular filtration. Exogenous creatinine originates from the metabolism of meat‑containing food in the body, whereas endogenous creatinine is derived from the metabolism of in‑vivo muscle tissue.

The detection principle of the Creatinine Content Assay Kit (Deproteinization Endpoint Method) is based on the Jaffe reaction between creatinine and picrate to form an orange‑red creatinine‑picrate complex. The amount of complex formed is proportional to creatinine concentration. The absorbance at 510 nm is measured using a microplate reader. This kit is applicable for determining creatinine content in human and animal plasma, serum and urine samples. This kit is for research use only and is not intended for clinical diagnosis or other applications.

Component

Component No.	Component Name	Appearance	100T	Storage
C1527215A	Creatinine Standard (10 mmol/L)	Liquid	1ml	2-8℃.Store in the dark.
C1527215B	Creatinine Standard Diluent	Liquid	10ml	RT
C1527215C	Protein Precipitation Solution	Liquid	50ml	RT.Store in the dark.
C1527215D	Cr Chromogenic Reagent	Liquid	5.5ml	RT
C1527215E	Cr Assay Buffer	Liquid	5.5ml	RT

Note: Store the unopened complete kit at 2‑8 °C protected from light; the shelf‑life is 12 months from the date of production. Components exhibit different stabilities after opening: Components C1527215B, C1527215C, C1527215D and C1527215E may be transferred for storage at room temperature while retaining the original 12‑month shelf‑life. Component C1527215A shall remain refrigerated.

Reagents, consumables and Equipments not provided

1. Distilled water

2. 1.5 mL centrifuge tubes, 96‑well microplate, centrifuge, microplate reader

Operating Procedure (For Reference Only)

1. Sample preparation: Prepare plasma and serum by conventional methods and store frozen at −20 °C. Mix 0.05 mL serum/plasma with 0.45 mL protein precipitation solution thoroughly. Allow to stand for 5 min, then centrifuge at 3500 r/min for 10 min. Collect the supernatant and store at 4 °C for later use. Urine contains high creatinine concentration; dilute urine 50‑ to 200‑fold with distilled water prior to assay.

2. Preparation of working standard solution: Mix Creatinine Standard (10 mmol/L) with Creatinine Standard Diluent at a volume ratio of 1:99 to obtain working standard solution (100 μmol/L). Store at 4 °C; valid for 1 week.

3. Cr sample loading: Set blank wells, standard wells and sample wells as shown in the table below. Add reagents sequentially and avoid bubble formation. If the creatinine concentration in sample is excessively high, reduce sample volume or dilute sample appropriately before measurement.

Additive (μL)	Blank Well	Standard Well	Sample Well
Distilled water	150	—	—
Creatinine Standard (100 μmol/L)	—	150	—
Deproteinized serum filtrate / diluted urine	—	—	150
Cr Chromogenic Solution	50	50	50
Cr Assay Buffer	50	50	50

4.Cr Detection: Mix thoroughly, incubate at room temperature for 15 min, measure the absorbance at 510 nm with a microplate reader. Set the blank well to zero, and record the absorbance of each well as A_Standard and A_Test, respectively. 

Calculations

Serum/plasma creatinine (μmol/L) = (A_Test / A_Standard) × 100 

Urine creatinine (μmol/d) = (A_Test / A_Standard) × 100 × N × 24h urine volume (L) 

Where: 

A_Test = Absorbance of the test well 

A_Standard = Absorbance of the standard well

N = Dilution factor of urine

Endogenous creatinine clearance (L/24h) = Urine creatinine (μmol/L) / Serum creatinine (μmol/L) × 24h urine volume (L)

Corrected endogenous creatinine clearance (L/24h) = Endogenous creatinine clearance × 1.73 / Body surface area (m²)

Note: Taking the normal 24h endogenous creatinine clearance value of 128 L (i.e., the creatinine in 128 L of blood is cleared by the kidneys within 24h) as 100%, then:

Endogenous creatinine clearance (%) = Corrected endogenous creatinine clearance × 100 / 128 (or × 0.78)

Unit conversion: d = 24h

Reference intervals

Healthy adult male serum creatinine: 44–133 μmol/L (0.5–1.5 mg/dL)

Healthy adult female serum creatinine: 70–106 μmol/L (0.8–1.2 mg/dL)

Healthy adult male creatinine clearance: 105 ± 20 mL/min

Healthy adult female creatinine clearance: 95 ± 20 mL/min

Precautions

1. Ensure all wells reach room temperature before measurement; otherwise results will be affected.

2. Slightly hemolyzed samples do not interfere with creatinine assay. Urine samples contain high creatinine content and shall be diluted 50‑200‑fold. If absorbance remains high after color development, further dilute urine and re‑test.

3. Absorbance of standard wells remains stable after color development, while absorbance of sample wells increases over time. Higher creatinine concentration leads to faster absorbance drift. Complete measurement within 30 min after chromogenic reagent addition.

4. Gradient assay with standard: concentrations below 200 μmol/L produce yellow‑orange yellow color. Color deepens gradually above 200 μmol/L to orange‑red, reaching dark orange‑red at 1000 μmol/L. For 100 μmol/L standard measured by microplate reader, absorbance is approximately 0.3.

5. Use reagents promptly after opening to avoid compromised assay performance.

6. For personal safety, wear lab coat and disposable gloves during operation.

Shelf‑life

Valid for 12 months.

Standard Curve Preparation

Cr(μmol/L)	0	20	50	100	150	200	400	700	1000
Absorbance	0.059	0.107	0.183	0.303	0.438	0.544	1.033	1.731	2.454

Specifications

Especificaciones y pureza

BioReagent, Standard Curve Method

Grado

BioReagent, Standard Curve Method

Aplicación

Cell Metabolism

Método de detección

Spectrophotometry

Detection instrument

Microplate reader

Detection wavelength

510nm

Sensibilidad

Light Sensitive

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 12 months under corresponding storage conditions.

Contents & Storage

Component No.	Component Name	Appearance	100T	Storage
C1527215A	Creatinine Standard (10 mmol/L)	Liquid	1ml	2-8℃.Store in the dark.
C1527215B	Creatinine Standard Diluent	Liquid	10ml	RT
C1527215C	Protein Precipitation Solution	Liquid	50ml	RT.Store in the dark.
C1527215D	Cr Chromogenic Reagent	Liquid	5.5ml	RT
C1527215E	Cr Assay Buffer	Liquid	5.5ml	RT