**Creatinine** |Procedure for Creatinine measurement |nchsls:c:biochemistry:document:examination_procedure:LDH|Electroinc-only document|Edition (1) 27-01-2014| |Electronic copy of the document is stored at NCHSLS server, NCHS, Surat| |Electronic copy of the document may be printed. However, It should be destroyed as early as possible after use, to ensure that only latest documentation is used every time.| |{{Creatinine_Reference_literature_1.pdf|Creatinine Reference literature 1}}| |{{Creatinine_Reference_literature_2.pdf|Creatinine Reference literature 2}}| |{{Creatinine_Reference_literature_3.pdf|Creatinine Reference literature 3}}| ===purpose of the examination=== The examination in serum and plasma is used mainly for diagnosis and management of renal disorders. Urine creatinine is frequently used as surrogate indicator to urine output ===principle and method of the procedure used for examinations=== Creatinine reacts with alkaline picrate to form red colored complex. After an incubation period, increase in absorbance between two time points is measured at 490-540 nm (psudo-first order kinetics).The incubation period and time points for measurement of absorbance are chosen to decrease interference from other compounds reacting with alkaline picrate with different kinetics. ===performance characteristics=== Linearity = 0-20[mg/dl] any one interval |{{Creatinine linearity check.ods|Creatinine linearity check}}|\\ Within Batch Precision = <7.5[% CV]\\ Between Batch Precision(IQC) = <10[%cv]\\ EQA Peer Precision = <10[%cv]\\ Measuring_Interval = 0-40[mg/dl]\\ Trueness_of_Measurement = >40[TS]\\ Analytical_Sensitivity = 0.0315[A/mg/dl]\\ ===type of sample=== [[nchsls:c:biochemistry:login_LIS|See Scope at Biochemistry LIS]] ===patient preparation=== [[nchsls:c:biochemistry:login_LIS|See Scope at Biochemistry LIS]] ===type of container and additives=== [[nchsls:c:biochemistry:login_LIS|See Scope at Biochemistry LIS]] ===required equipment and reagents=== |[[Creatinine reagent]]| ===environmental and safety controls=== |{{msds_lithium lactate.pdf|MSDS of Lithium lactate}}| |{{msds_DEA.pdf|MSDS of DEA}}| |{{msds_NAD+.pdf|MSDS of NAD+}}| ===calibration procedures (metrological traceability)=== ===procedural steps=== XL-640 Filter 340 nm\\ Temperature 37 degree C\\ Method Rate-A\\ Step-1 200 microliter R1\\ Step-2 10 microliter Sample\\ Step-3 M1S=0 M1E=0 M2S=3 M2E=8\\ Step-4 Reagent Absorbance Max=0\\ Step-5 Reagent Absorbance Min=0\\ Step-6 Reaction Absorbance limit=0\\ Step-7 Technical Min=0\\ Step-8 Technical Max=1000\\ Step-9 Linearity limit%=0\\ Step-10 Delta Abs/min%=0\\ Step-11 Reaction direction=Increasing\\ ===quality control procedures=== Internal Qc 3 times a day at 8 AM , 3 PM , 10 PM.\\ External Qc once in a month ===interferences (e.g. lipaemia, haemolysis, bilirubinemia, drugs) and cross reactions=== More than 400[mg/dl Hemoglobin]\\ More than 30[mg/dl Total Bilirubin]\\ More than 12[mg/dl ascorbate]\\ More than 700[mg/dl Triglyceride] ===principle of procedure for calculating results including, where relevant, the measurement uncertainty of measured quantity values=== ===biological reference intervals or clinical decision values=== ===reportable interval of examination results=== [[nchsls:c:biochemistry:login_LIS|See Reportable ranges at Biochemistry LIS]] ===instructions for determining quantitative results when a result is not within the measurement interval=== ===alert/critical values, where appropriate=== [[nchsls:c:biochemistry:login_LIS|See Critical ranges at Biochemistry LIS]] ===laboratory clinical interpretation=== ===potential sources of variation=== ===references===