cc chapter 5

Light energy

Form of electromagnetic radiation that carries energy

Spectrophotometer

Light is used to measure the concentration of substance in a sample

Electromagnetic radiation

Energy that travels in a form of waves

Wavelength

Distance between two consecutive peaks

Frequency

Number of wave cycles passing a point in one second

Planck’s equation

Relationship between energy and frequency is described by

Ultraviolet

Dna analysis, protein measurement, enzyme assays

Visible light

Routine clinical tests: glucose cholesterol creatinine total protein

Spectrophotometry

Measures the amount of light transmitted or absorbed by solution

Beer lamberts law

The more concentrated the solution, the more light it absorbs and less light passes through

Infared

Water analysis molecular identification specialized laboratory instruments

Light/radiant source

Provides light needed for analysis

Tungsten iodine lamp

Most common used light

Hollow cathode lamp

Absorption spectrophotometry

Deuterium discharge lamp/mercury arc lamp

Most commonly used in UV

Entrance slit

Minimizes stray light

Monochromator

Isolates the specific wavelength of light needed for th measurement

Exit slit

Allows only a narrow fraction of light

Cuvette

Holds the solution

Photodetector

Detects and converts transmitted light into photoelectric energy

Read out device

Displays the output

Flame emission photometry

Introduced to flame

Sodium,potassium,lithium,rubidium,magnesium

Yellow,violet,red,red,blue

Atomic absorption spectrophotometry

Measure the amount of metal in a sample

Chemiluminescence

Without the need for an external light source

Turbidimetry

How much light is blocked

Nephlometry

Measures the amount of light scattered, measures protein and antigen antibody complexes

Chromatography

Separation pf soluble components in a solution

Electrophoresis

Applying an electric current through a supporting medium

Stationary phase

Phase that does not move

Mobile phase

Phase that moves

Paper chromatography

Uses whatman filter, separate the paper components of a mixture

Thin layer chromatography

Separation technique which a thin layer of silica or aluminum serves as the stationary phase. While a solvent acts as a mobile phase

Gas chromatography

Mobile phase

Inert gas helium/ nitrogen

Gas chroma Mass spectrophotometry

Goldstandard for drug testing

Glucose

Diabetes mellitus, hypoglycemia 505

Albumin

liver disease, nephrotic syndrome, malnutrition 630(BCG)

Urea

Kidney disease, dehydration 340 (UV)/578(berthelot)

Creatinine

Kidney disease,renal failure,510(jaffe)

Uric acid

Gout,renal disease 520

Total cholesterol

Cardiovascular disease,hyperlipidemia, 500

Triglycerides

Hyperlipidemia,metabolic syndrome 500

HDL

Coronary artery disease risk 600

LDL

Atherosclerosis,cardiovascular disease 600

Total bilirubin

Liver disease,hemolytic anemia,jaundice 546

Direct bilirubin

Obstructive jaundice,hepatitis 600

AST(SGOT)

Liver disease,myocardial infarction,muscle injury 340

ALT(SGPT)

Liver disease,hepatitis 340

Alkaline phosphatase

Bone disease,cholestasis,liver disease 405

Gamma-glutamyl transferase

Alcoholic liver disease,biliary obstruction 405

Lactate dehydrogenase

Tissue damage,hemolysis,myocardial infarction 340

Creatinine kinase

myocardial infarction,skeletal muscle injury 340

Amylase

Acute pancreatitis 405

Lipase

Acute pancreatitis 580

Calcium

Bome disorders,hyperparathytoidism 650-660

Phosphorus

Kidney disease,bone disorders 340

Magnesium

Neuromuscular disorders,kidney disease 520

Iron

Iron deficiency anemia,hemochromatosis 560

Lactate

Sepsis, tissue hypoxia 340

Ammonia

Hepatic encephalopathy,liver failure 340