Lecture (week2)

Question 1

preferred in
scientific literature and clinical laboratories and is the only system used in many countries

o Accepted internationally
o Provides global scientific community a uniform method of describing physical quantities

Answer 1

Système International d’Unitès (SI)

Question 2

o Derivative or a mathematical function of one of the
basic units
o Example: m/s; still from base unit; can be
expressed using different parameter

Answer 2

Derived unit

Question 3

o Widely used that they have become acceptable for
use with SI basic or SI derived units

Answer 3

Some Non-SI units

Question 4

o When added to a given unit, it can indicate decimal
fractions or multiples of that unit
o Important note:
▪ The SI term for mass is kilogram or Kg. It is
the only basic unit that contains a prefix as
part of its naming convention

Answer 4

SI uses standard prefixes

Question 5

• Electronic transmission of laboratory data and the more routine use of an electronic medical record, coding,
  billing, and other data management systems may vary.
  o Varies from one institution to another. Depends on
  the SOP.

Answer 5

ELECTRONIC REPORTING OF RESULTS

Question 6

• A substance that is used to test for the presence of another substance by causing reaction with it.
• Any substance employed to produce a chemical reaction

Answer 6

REAGENTS

Question 7

substances that occurs naturally or is obtained through a chemical process. These analytical chemicals used in
the laboratory exists in varying grades of purity.

Answer 7

CHEMICALS

Question 8

I. Analytical Reagent (AR)
II. Ultrapure
III. Chemically Pure (CP)
IV. United States Pharmacopeia (USP)
V. National Formulary (NF)
VI. Technical or Commercial Grade

Answer 8

CHEMICAL GRADES OF PURITY (INORGANIC REAGENTS)

Question 9

o Highest grade of purity
o Established by ACS- American Chemical Society
o used for qualitative and quantitative analysis in
the laboratory
o used for special testing in the lab: trace metal
analysis and preparation of standard solutions

Answer 9

Analytical Reagent (AR)

Question 10

o Additional purification which could be more sensitive
o Used for chromatography, atomic absorption spectrophotometry, molecular assays, molecular diagnostic for standardization, or other techniques
that require extremely pure chemicals

Answer 10

Ultrapure

Question 11

o Pure grade
o Purity of the chemical is specified by the
manufacturers
o Chemically pure substances fail to reveal the tolerance limit of its impurities
o Not intended for research and analytical chemistry

Answer 11

Chemically Pure (CP)

Question 12

o Pure enough to use in most chemical procedures however, it should be recognized that the purity standards are not based on the needs of the laboratory.
o May or may not meet all assay requirements.
o Good for human consumption
o Used in drug manufacturing

Answer 12

United States Pharmacopeia (USP)

Question 13

o Same characteristics as USP

Answer 13

National Formulary (NF)

Question 14

o Not used in clinical laboratory testing and only used in manufacturing industry

Answer 14

Technical or Commercial Grade

Question 15

Also have varying grades of purity that differs from those used to classify inorganic reagents

Answer 15

Organic Reagents

Question 16

o Practical grade with some impurities

Answer 16

o Chemically pure
o Spectroscopic
o Chromatographic

Question 17

It approaches the purity level of reagent
grade

Answer 17

Chemically pure

Question 18

Spectrally pure

Answer 18

Spectroscopic

Question 19

The minimum purity of 99% could be
obtained only by gas chromatography

Answer 19

Chromatographic

Question 20

o highly purified chemical that can be measured directly to produce a substance of exact known concentration and purity; purest

o ACS purity tolerance test for primary standard should be 100% ± 0.02%; equal to perfection

o Most biologic constituents are unavailable within
this limitation

Answer 20

Primary standard

Question 21

Used in place of an ACS primary standard in clinical work and is often used to verify
calibration or accuracy of assessment/testing

Answer 21

NIST: Standard/Certified Reference Material (SRM/CRM)

Question 22

o substance of lower purity with concentration determined by comparison with a primary standard

o prepared solution whose concentration is determined by testing

Answer 22

Secondary Standard

Question 23

the most frequently used reagent in the
laboratory.

Answer 23

Water

Question 24

o Distillation (distilled water)
o Ion exchange (deionized water)
o Reverse Osmosis
o Other purification processes: Ultrafiltration,
Ultraviolet Light, Sterilization, Ozone Treatment

Answer 24

Purification

Question 25

o Classification according to CLSI as: Clinical laboratory reagent water (CLRW), Special reagent water (SRW), Instrument feed water, Water supplied by method manufacturer, Autoclave and wash water, and commercially bottled purified water.

Answer 25

Reagent Grade Water

Question 26

remove particulate matter for municipal water supplies before any additional treatments o Glass, cotton (to filter more particulate matter), activated charcoal (remove organic materials, even chlorine), submicron filters (≤ 0.2 mm; remove substances like bacteria)

Answer 26

Prefiltration

Question 27

water has been purified to remove almost all organic materials o Water is boiled and vaporized. o Water can be distilled more than once with each distillation cycle removing additional impurity

Answer 27

Distillation

Question 28

water has some or all ions removed o Although ions are removed, organic materials may still be present o If water goes ion exchange treatment, it is neither pure nor sterile

Answer 28

Ion exchange

Question 29

process that uses pressure to force water through a semipermeable membrane o Water that reflects a filtered product of the original water is an RO water o In RO, it does not remove dissolved gasses. o At most cases, reverse osmosis may be used as a pre-treatment of water.

Answer 29

Reverse Osmosis

Question 30

excellent in removing particulate matter, microorganisms, and any pyrogens or endotoxins o Through ultraviolet oxidation, organic materials are removed. Sterilization processes, together with ozone treatment, removes bacteria, other microorganisms, or other residual products

Answer 30

Ultrafiltration & Nanofiltration:

Question 31

Most pure - ideal for special testing in the laboratory; trace metal determination, ion determination, enzyme analysis, tissue or cell culture, and the likes. Silicate content and resistivity goes hand in hand. The less silicate content, the more the water is resistant. The more the water is resistant (less conductive), the more the water is pure.

Answer 31

Type I

Question 32

still acceptable in most analytical requirements. Used in quality control, reagent preparation, and laboratory determination.

Answer 32

Type II

Question 33

Type III

Answer 33

not ideal for analysis or reagent preparation

Question 35

Analytical reactions occur in optimal temperatures. o Liquid in glass: usually measure temperatures between 20°C and 400°C o Electronic / Thermistor probe: smaller and has millisecond response time o Digital

Answer 35

Thermometers

Question 36

are calibrated in the laboratory to make sure that accurate temperature is obtained. Calibrator: gallium

Answer 36

Thermometers

Question 37

Differ on their ability to resist acid and alkaline solution and thermal resistance.

Answer 37

Glassware

Question 38

▪ Ideal for heating and sterilization processes ▪ Has high thermal resistance ▪ Example: Pyrex, Kimax

Answer 38

Borosilicate Glass

Question 39

▪ Soda lime glass ▪ Inexpensive but has low resistance to temperature and chemical ▪ Easy to melt ▪ Usually, a disposable glassware (petri dish)

Answer 39

Flint Glass

Question 40

▪ Silica glass ▪ Quite expensive ▪ Used when excellent light transmission is needed ▪ Used for cuvettes (holds solution in spectrophotometer)

Answer 40

Quartz Glass

Question 41

▪ Soft glass ▪ High resistance to alkaline solution

Answer 41

Boron-free

Question 42

▪ Corex ▪ Strengthened chemically than thermally ▪ Chemically-wise, 6x stronger than borosilicate glasses

Answer 42

Aluminosilicate

Question 43

▪ Used for high thermal requirement ▪ Could be heated up to 900⁰C ▪ Acid and alkaline resistant

Answer 43

Vycor

Question 44

▪ Amber glasses; light protection

Answer 44

Low-actinic

Question 45

Somehow begins to replace glassware in laboratory setting. Plasticwares are unique and high resistance supplies- resistance to corrosion and breakage. Inexpensive compared to glassware.

Answer 45

Plasticwares

Question 46

▪ Unique group of resins unaffected by acids, alkaline, salt, and aqueous solutions ▪ Can be autoclaved ▪ Two types * Polypropylene * polyethylene

Answer 46

Polyolefins

Question 47

▪ 2x stronger as compared to propylene ▪ Can resist temperature up to 100-160⁰C ▪ Dissolved in chlorinated aliphatic or aromatic hydrocarbons

Answer 47

Polycarbonate resins

Question 48

▪ Non-toxic, clear, can handle different chemicals ▪ Can be steamed, autoclaved, or chemically sterilized ▪ Flexible at around 30⁰C or brittle at around 45⁰C

Answer 48

Tygon

Question 49

▪ Can resist extreme temperature of up to -270⁰C to 255⁰C

Answer 49

Teflon-fluorocarbon resin

Question 50

- Generally: - Blood clots - New pipets - Metal ion determination - Grease - Bacteriologic - Permanganate stains

Answer 50

CLEANING OF LABWARE

Question 51

o Soapy water/ dilute bleach solution o Acid dichromate o 20% Nitric Acid

Answer 51

Generally:

Question 52

o 10% sodium hydroxide

Answer 52

Blood clots:

Question 53

o 5% hydrochloric acid o 5% nitric acid

Answer 53

New pipets:

Question 54

o 20% nitric acid

Answer 54

Metal ion determination:

Question 55

o Potassium hydroxide and 10% ethanol o Contrad 70

Answer 55

Grease:

Question 56

o 2-4% cresol

Answer 56

Bacteriologic:

Question 57

o 50% hydrochloric acid o 25% sulfuric acid

Answer 57

Permanganate stains

Question 58

o calibrated to hold one exact volume of liquid (TC) o has a round, lower portion with a flat bottom and a long, thin neck with an etched calibration line. o Used to bring a given reagent to its final volume with a prescribed diluent

Answer 58

Volumetric flask

Question 59

o designed to hold different volumes rather than one exact amount o Erlenmeyer flask has a wide bottom that gradually evolves into a smaller, short neck o Griffin beaker has a flat bottom, straight sides, and an opening as wide as the flat base, with a small spout in the lip. o Used for preparation of reagent o Designed to hold different volumes rather than a single amount; has different graduations unlike volumetric flask

Answer 59

Erlenmeyer flasks and Griffin beakers

Question 60

o has calibration marks along its length and is used to measure volumes of liquids o long, cylindrical tubes usually held upright by an octagonal or circular base o do not have the accuracy of volumetric glassware it has calibration marks along its length o used to measure different volumes of fluid which could vary from 10mL, 25 mL, 50 mL, etc.

Answer 60

Graduated cylinders

Question 61

- instrument used to transfer liquids from one vessel to another - Glass or plastic utensils used to transfer liquids; they may be reusable or disposable - Designed to contain (TC) or to deliver (TD) a particular volume of liquid

Answer 61

PIPETS

Question 62

PIPET DESIGN

Answer 62

To Contain (TC) To Deliver (TD)

Question 63

o holds or contains a particular volume but does not dispense that exact volume

Answer 63

To Contain (TC)

Question 64

will dispense the volume indicated

Answer 64

To Deliver (TD)

Question 65

PIPET DRAINAGE CHARACTERISTICS

Answer 65

Blowout and Self-draining

Question 66

o has a continuous etched ring or two small, close, continuous rings located near the top of the pipet o the last drop of liquid should be expelled into the receiving container; exact volume is only obtained when the last drop is blown out

Answer 66

Blowout

Question 67

o the user allows the contents of the pipet to drain by gravity

Answer 67

Self-draining

Question 68

Measuring or Graduated Pipets PIPET TYPES

Answer 68

A. Mohr B. Serologic: C. Micropipet

Question 69

does not have graduations to the tip o self-draining pipet, but the tip should not be allowed to touch the vessel while the pipet is draining o calibrated in between two marks

Answer 69

Mohr

Question 70

has graduation marks to the tip\ o used for the measurements of reagents and are not generally considered accurate enough for measuring viscous samples and standards o Blowout pipet

Answer 70

Serologic

Question 71

with a total holding volume of less than 1 mL - may be designed as either a Mohr or serologic pipet

Answer 71

Micropipet

Question 72

- Ostwald-Folin - Volumetric - Pasteur - Automatic

Answer 72

Transfer Pipets

Question 73

used with biologic fluids having a viscosity greater than that of water o blowout pipets, indicated by two etched continuous rings at the top o ideal for transferring viscous solution o has a bulb near the tip of the pipet

Answer 73

Ostwald-Folin

Question 74

designed to dispense or transfer aqueous solutions and is always self-draining o has the greatest degree of accuracy and precision and should be used when diluting standards, calibrators, or quality-control material o has a bulb at the middle of the pipet o designed to deliver a fixed volume of aqueous solution

Answer 74

Volumetric

Question 75

do not have calibration marks and are used to transfer solutions or biologic fluids without consideration of a specific volume o not used in any quantitative analytic techniques o disposable pipets o may or may not have calibration marks

Answer 75

Pasteur

Question 76

most routinely used pipet in today’s clinical chemistry laboratory o Safe, stable, high precision, saves time, less cleaning required

Answer 76

Automatic

Question 77

can aspirate and transfer only a single volume

Answer 77

Fixed

Question 78

different volumes however, only one volume can be used at a time

Answer 78

Variable

Question 79

relies on a piston for suction creation to draw the sample into a disposable tip that must be changed after each use

Answer 79

Air Displacement

Question 80

operates by moving the piston in the pipet tip or barrel, much like a hypodermic syringe ▪ the piston itself moves into the pipet tip, like in syringe. ▪ Does not require a different tip for each time. ▪ There is a possible carry over at times

Answer 80

Positive Displacement:

Question 81

obtain the liquid from a common reservoir and dispense it repeatedly ▪ May be bottle top, motorized, handheld

Answer 81

Dispenser

Question 82

- looks like a wide, long, graduated pipet with a stopcock at one end - used to dispense a particular volume of liquid during a titration - used in quantitative chemical analysis used to measure the volume of a liquid

Answer 82

BURETS

Question 83

- Sometimes used for transfer of small volumes in blood gas analysis or in separation techniques such as chromatography or electrophoresis o Used if < 500 µL of solution - Glass and have fine barrels

Answer 83

SYRINGES

Question 84

o Drying agents to make sure that your chemical is free from any moisture that may alter testing o Placed below the perforated platform of a desiccator o keep other chemicals from becoming hydrated o most effective when placed in a closed, airtight chamber called a desiccator o In the laboratory, desiccants are primarily used to prevent moisture absorption by chemicals, gases, and instrument components.

Answer 84

Dessicants

Question 85

required for the preparation of any primary standards o mechanical analytic balance is also known as a substitution balance

Answer 85

Analytical Balance

Question 86

uses an electromagnetic force to counterbalance the weighed sample’s mass - measurements equal the accuracy and precision of any available mechanical balance, with the advantage of a fast response time

Answer 86

Electronic Balance

Question 87

- Separates solid from a liquid suspension by means of a centrifugal force - A process in which centrifugal force is used to separate solid matter from a liquid suspension - Centrifugal force: mass, speed, and radius o Speed: rpm o Centrifugal force generated: RCF or g 𝑅𝐶𝐹 = 1.118 × 10−5 × 𝑟 × (𝑟𝑝𝑚) 2

Answer 87

Centrifugation

Question 88

o daily cleaning of any spills or debris o balancing the centrifuge load o centrifuge cover should remain closed until the centrifuge has come to a complete stop

Answer 88

Centrifuge Care

Question 89

sed to check the speed of a centrifuge o In using a centrifuge, make sure that it is covered from start to finish to avoid aerosol contamination o Do not manually stop a centrifuge. Wait for it to stop itself.

Answer 89

Tachometer or Strobe Ligh

Question 90

- Used for the separation of solids from liquids - Filter material is made of paper, cellulose and its derivatives, polyester fibers, glass, and a variety of resin column materials - Filter papers differ in pore size o Should be selected according to separation needs - Filter paper should not be used when using strong acids or bases

Answer 90

Filtration

Question 91

Liquid that passes through the filter paper

Answer 91

FILTRATE

Question 92

- Used for separating macromolecules from a solvent or smaller substances - Large particles from small particles

Answer 92

Dialysis

Question 93

: fluid that passes

Answer 93

Dialysate

Question 94

fluid that did not pass

Answer 94

Retentate

Question 95

- Freeze drying o Liquid to powder-like

Answer 95

Lyophilization

Question 96

- separation of compounds, based on their relative solubilities in two different immiscible liquids or solid matter compound - 2 Types: o Liquid-Liquid Extraction o Solid-Liquid Extraction

Answer 96

Extraction

Question 97

o Quantitative measurement of different chemical constituents of blood

Answer 97

Blood

Question 98

o Checking of kidney functions ▪ Glomerular filtration rate

Answer 98

Urine

Question 99

o Measurement of glucose and protein

Answer 99

CSF

Question 100

SPECIMENS IN CLINICAL CHEMISTRY

Answer 100

- Blood - Urine - CSF - Pleural fluid - Pericardial fluid - Peritoneal fluid - Amniotic fluid