Clinical Chemistry Exam 1 Latest Update Graded A

Clinical Chemistry Exam 1 Latest Update Graded A Accuracy The closeness with which a measurement comes to the true value Precision The degree of reproducibility in the measurement of a substance Mean Sum of all of a set divided by the number in the set (average) Median The point on the scale that has equal number of observations above and below (even number, take the two-center numbers add and divide by 2) Mode The value in a set that occurs most frequently Norm. Distribution The theoretical bell-shaped curve based in the Gaussian Law of Errors. Normal Frequency Curve Standard Deviation A statistical calculation that measures the scatter of sample values around the mean. (The acceptable variation from the mean) The clinical lab uses 2 SD as an acceptable variation in a method of analysis. Confidence Limits An expression of the amount of error that can be allowed in the recovery of a value without affecting the validity Coefficient of Variation An expression of standard deviation as a percentage of the mean A way of comparing the precision of different methods of assay Also a better way to check the precision at various levels of concentration Bias A constant departure of quantity from the true value due to outside influence Random Error An error that does not occur in any regular predictable pattern Systematic Error A regularly occurring error that is constant, predictable, and traceable Shift Six to ten control values fall consecutively above or below the mean Trend An uninterrupted rise or decline away from the mean Primary Standard A solution generally containing a single purified solute in a pure solvent The true value of the solvent is known by exact measurement (Analytical Balance) Used to "set" or calibrate an instrument Secondary Standard A material with an established value(s) determined by assay against a primary standard It may contain one or more constituents Control Usually pooled human sera containing a number of substances used to verify the precision of a method Mole Atomic Weight Molarity Atomic Weight/1 Liter (1000 mL) Normality N = Eq/L (1000mL) Equivalent Weight Equivalents = Molecular weight/Vē Percent Parts per 100 Weight/Volume% g/mL Volume/Volume% mL/100mL Weight/Weight% g/100g Concentration Formula from High to Low V₁C₁= V₂C₂ Magic Formula Molecular Wieght x Normality = Grams/Liter CLRW Clinincal Laboratory Reagent Water Analyte Substance of interest Serum Does not contain fibrogin Plasma Contains fibrogin Type I water Most pure Type II water Most use for Lab Procedures Type III Water used to rinse glassware Chemical used NOT use for lab Technical, Commercial, USP purified Chemical USED for lab Analytical, Reagent Air Displacement Micro pipette air forces ejection Positive Dicplacement Plunger pushes out liquid Quality Assurance a program of measures taken by health care providers and practitioners to uphold the quality of patient care Quality Control inclusive lab procedures as standards to provide reliable performance of equipment including test control samples documentation and analyzing statistics for diagnosis tests Glycogen Storage form of glucose Glyconegenisis creation of glycogen glycogenolysis breakdown of glycogen to glucose Gluconeogenisis formation of glucose from non-carbohydrate sources such as amino acids, glycerol or lactate. Occurs during fasting Glycolysis conversion of glucose or other hexoses into 3C Normal Glucose Level 70-100 Insulin hormone secreted by the isles of Langerhans in the pancreas glucogen pancreatic hormone released to increase blood glucose Spectrophotometry An analytical method for identifying a substance by its selective absorption of different wavelengths of light. Parts of the Spectrophotometer Power Source Light Source Monochromater - Wave Length Selecter Sample Cuvet Detector - Converts LE to EE Read out device AAS Atomic Absorption Sectometer Detects absorption of electrmaganetic radiation of ground state atoms, used specifically for trace metals and other ions such as zinc, lead, mercury, arsenic, and copper Flame Photometry Measures the intensity of emittedlight when element is returning to ground state Old method used to measure Na, K and Li Specimen diluted 1:200 High amount od Lipid and protein could lead to false readings Electrodes Detectors that are sensitive to the potential differences (change in charge) that build up at an interface when two different concentrations of the same ions are in contact with one another Consist of an indicator electrode and a reference electrode pH meter first to be used ISA modification widely used today Fluorometry measures amt of flourescence after exposure to light of certain wavelength Not all molecules will flouresce Quenching may be a problem Very sensitive and specific florescence polorarization very popular Chemiluminescense Similar to Flourometry but no excitation required Chemical reaction (oxidation) involving specimen produces emission of light Many time involves luminol and a luminometer Nephelometry this principle of light measurment measures scattered light Detector placed at an angle Lasers are often used as the light source Electrophoresis a technique for the seperation of molecules through their migration on a support medium while under the influence of an electrical potential Used to separate serum proteins and also for hemoglobin separation Chromatography the general name for a series of methods for separating mixtures by employing a system with a mobile phase and a stationary phase RIA and immunochemical Methods RIA EMIT ELISA FIA all involve ag/ab complexing