CC1 Instrumentation CC PDF

CLINICAL CHEMISTRY John Leo C. Dayrit, RMT INSTRUMENTATION TYPES OF GLASSWARES 1.Borosilicate glass (Pyrex and Kimax) it is used for heating and sterilization purposes; most commonly used. it is characterized by a high degree of thermal resistance, has low alkali content, and is free...

CLINICAL CHEMISTRY John Leo C. Dayrit, RMT INSTRUMENTATION TYPES OF GLASSWARES 1.Borosilicate glass (Pyrex and Kimax) it is used for heating and sterilization purposes; most commonly used. it is characterized by a high degree of thermal resistance, has low alkali content, and is free from the magnesium, lime- zinc group of elements, heavy metals, arsenic, and antimony. strain point: 515° C(Pyrex) 2. Boron-free glassware/Soft glass it has high resistance to alkali. its thermal resistance is less as compared to borosilicate glass. 3. Corex (Corning) is a special alumina-silicate glass that has been strengthened chemically than thermally; six times stronger than borosilicate. 4.Vycor (Corning) it is utilized for high thermal, drastic heat shock and extreme chemical treatment with acids (except hydroflucric) and dilute alkali; it can be heated to 900°C. 5. Flint glass it is made up of soda-lime glass and a mixture of calcium, silicon and sodium oxides it has poor resistance to high temperature - easy to melt and used to make disposable glasswares Pipette Classification: 1. Calibration Marks/Design: To Deliver (TD) - it delivers the exact amount it holds into a container To Contain (TC) - it holds the particular volume but does not dispense the exact volume 2. Drainage Characteristics: Blowout - it has a continuous etched rings on top of the pipet; exact volume is obtained when the lastdrop is blown out Self-draining - absence of etched rings; liquid is allowed to drain by gravity 3. Types:.A.Transfer Pipette Volumetric Pipet - for nonviscous fluid; self-draining; smal amount left ni the tip should not be blown out Ostwald Folin - for viscous fluid; with etched ring Pasteur Pipet - transfers fluids without consideration of a specific volume Automatic macro-or micropipettes B. Graduated or Measuring Pipet Serological Pipet - with graduations to the tip; blowout pipet Mohr Pipet- without graduations to the tip; calibrated between 2 marks; self-draining Mechanical or Automatic Pipettes a. Air Displacement Pipet It relies on piston for suction creation to draw the sample into a disposable tip The piston does not come in contact with the liquid. b. Positive Displacement Pipet It operates by moving the piston in the pipet tip or barrel, r u c h like a hypodermic syringe. It does not require a different tip for each use. c. Dispenser/Dilutor Pipet It obtains liquid from a common reservoir and dispensed it repeatedly. * It combines sampling and dispensing functions. For Calibration of Pipettes: Class Apipets do not require recalibration. Distilled water is the calibrating medium for TD pipettes while mercury is for TC pipettes. * Gravimetric and spectrometric methods - used to verify pipette volume accuracy and precision 0.1% phenol red solution in distilled water —used tu compare the reproducibility of brands of pipe tips Volume Measurements: 1 lambda = 1 microlite: (0.001 mL) 1 microliter = 1.0 milligram Calibration of Analytical Balance and Thermometer Analytical Balance Laboratory balances require calibration at regular intervals - calibration intervals should coincide with the requirements of the laboratory's licensing and accrediting organizations. The new mass standards and test weight accuracy classes appropriate for laboratory balances include the American Society for Testing and Materials (ASTM) classes 1 and 2 The operator must avoid direct contact with the weights by using clean gloves or special lifting tools (e.g., forceps). Hand contact with the weights can cause corrosion. Thermometer 2 types of thermometers: total immersion (freezers and refrigerators) partial immersion (water baths and heating blocks) Noncertified thermometers can be calibrated by using an NIST SRM934 thermometer or an NIST SRM 1969 gallium melting point cell. Temperature-monitoring devices st.ould be verified for accuracy at 6 or 12 month intervals.  AUTOMATION in medical technology involves the use of advanced machines, software, and robotics to perform diagnostic, therapeutic, and administrative tasks in healthcare. This automation enhances efficiency, accuracy, and safety, ultimately improving patient care and reducing healthcare costs Advantages Increase the number of tests to be performed in a given period. Minimizes variation of result from one laboratorian to another. Eliminates the potential error in manual analyses such as pipetting, calculation and transcription of results.  Uses of automation Reduce human Safety & Decreased Improved turn- error increased laboratory around time productivity costs and run more tests 1.Continuous Flow Analyzer Liquids are pumped through a system of continuous tubing. Samples flow through a common reaction vessel or pathway. Air bubbles at regular intervals serve as separating and cleaning media. A heating bath maintains the required temperature of the reaction to allow complete color development (same with discrete analyzers) - reaction rate is controlled by temperature. Mixing of sample and reagents: by using a glass coil inserted into the flow path Example: Simultaneous Multiple Analyzer (SMA), Technicon Disadvantage: all tests are performed in parallel (measurement of every analyte configured on the system for every sample) Disadvantages of continuous flow analyzer 1. The machine does not allow this election all tests must be performed even if not requested. 2. The machine must run even when there are no tests/procedures being done. 3. Because of the continuous flow the reagent must be drawn at all times even when there are no tests to perform which results in Reagent wasting 4. They usually occupy large amount of spaces. 2. Centrifugal Analyzer It uses the force generated by centrifugation to transfer specimen and reagents. Liquids are placed ni separate cuvettes for measurement at the perimeter of a spinning rotor (1000 rpm). It uses acceleration and deceleration of the rotor to transfer the reagents and sample from one chamber to another. Mixing: centrifugal force (rotor) is utilized or bubbling of air Major advantage: Batch analysis (discrete-batch type system) Examples: Cobas-Bio (Roche) and LI Monarch 3. Discrete Analyzer It is the most popular and versatile analyzer - measures only the tests requested on a sample. It employs a variety of syringe pipettes (positive liquid-displacement pipets) to aspirate and dispense samples and reagents. It is capable of running multiple-tests-one-sample-at-a-time. Each sample-reagent mixture handled separately in its own reaction vessel. For dry slide technology (reflectance photemetry), the spreading layer permits a rapid uniform spreading layer over the reagent layer. Mixing: magnetic driven teflon stirring bar, forceful dispensing, magnetic stirring bars, rotating paddle, and ultrasonic energyxamples: Vitros, Dimension Dade, Beckman ASTKA System, Hitachi, Bayer Advia, Roche Cobas Integra Major advantage: Random access capability - allows STAT samples to be easily tested Reflectance photometry It is the measurement of light reflected from solid surfaces. The intensity of the reflected light from the reagent carrier is compared with the intensity of light reflected from a reference surface. Areflectometer is used to measure analytes by measuring the quantity of light reflected by a liquid sampie that has been dispensed or to a grainy or fibrous solid support. Common Terminologies: 1. Batch testing - all samples are loaded at the same time, and a single test is conducted on each sample 2. Parallel testing - more than one test is analyzed concurrently on a given clinical specimen 3. Random access testing- any test can be performed on any sample in any sequence 4. Sequential testing - multiple tests analyzed one after another on a given specimen 5. Open reagent system - a system other than manufacturer's reagents can be utilized for measurement 6. Closed reagent system- a system where the operator can only used the manufacturer's reagents 7. Pneumatic tube delivery system- it provides point-to-point delivery of specimens to the laboratory and offered several advantages over specimen transport by humans