Micropipettes and Beer-Lambert Law Quiz

Micropipettes

• Essential laboratory tools for measuring and transferring small liquid volumes, typically in microliters
• Components: Plunger, volume adjustment dial, tip ejector button, tip holder
• Functional steps: Set volume, attach tip, aspirate liquid, dispense liquid, eject tip
• Types: Single-channel, multi-channel, variable volume, fixed volume

Using a Micropipette

• Select a micropipette with a volume range encompassing the desired volume
• Set the desired volume using the plunger or adjustment dial
• Securely attach a sterile tip
• Submerge the tip into the liquid and press the plunger to the first stop to aspirate liquid
• Avoid air bubbles
• Position the tip over the target and press the plunger to the second stop to fully dispense the liquid
• Avoid touching surfaces during dispensing
• After dispensing, safely eject the tip

The Beer-Lambert Law

• Relates the absorbance of a solution to the concentration of the dissolved substance
• Absorbance is directly proportional to concentration
• Equation: A = a b c
• A: absorbance, a: molar absorptivity coefficient, b: light path through the solution, c: concentration

Spectrophotometer

• Instrument used to measure transmitted light through a solution, allowing for the determination of the concentration of a light-absorbing substance
• Components: Light source, monochromators, sample cell (cuvette), photodetectors, meter

Drawing Blood & Sampling

• Requires proper training and knowledge to avoid complications such as infections and tissue damage
• Blood samples are collected from blood vessels by trained personnel
• Equipment: Tourniquet, alcohol swabs, gloves, needles, blood collection tubes, bandage
• Steps: Prepare patient, gather supplies, apply tourniquet, locate a vein, clean the site, insert needle, collect blood, remove needle, apply pressure, secure the site

Glucose

• Primary energy source for living organisms
• A carbohydrate (monosaccharide), specifically a hexose with the formula C6H12O6
• Also known as dextrose or grape sugar

Hypoglycemia

• Low blood glucose level
• Causes: Too much insulin, too much exercise, not enough food
• Symptoms: Sweating, weakness, hunger, headache

Hyperglycemia

• High blood glucose level, often associated with diabetes
• Causes: Not taking enough insulin, illness, eating too much, certain medications
• Symptoms: Blood glucose over 240 mg/dl, increased urine output, thirst, dry skin and mouth

Diabetes Mellitus

• Group of metabolic diseases characterized by hyperglycemia due to deficiencies in insulin secretion, action, or both
• Types: Type 1 (IDDM), Type 2 (NIDDM), Gestational diabetes
• Different glucose blood tests: Fasting blood glucose, oral glucose tolerance test (OGTT), random blood sugar, hemoglobin A1c (HbA1c)

Protein

• Large biological macromolecules composed of one or more long chains of amino acid residues
• Perform a vast array of functions within living organisms
• Total serum protein test measures total protein, albumin, and globulin levels in blood

Albumin

• Primarily produced in the liver
• Helps maintain blood vessel integrity, transporting substances, and tissue growth and healing

Globulin

• Composed of different proteins (alpha, beta, gamma)
• Some produced by the liver, others by the immune system
• Functions include binding with hemoglobin, transporting metals, and immune system activity

Protein Structure

• Four levels: Primary (amino acid sequence), secondary (alpha helix, beta sheet, turns), tertiary (overall shape of a single protein molecule), quaternary (interaction of multiple polypeptide chains)

High Protein Levels

• High albumin: Severe dehydration
• High globulin: Diseases of the blood, autoimmune diseases, kidney disease, liver disease

Low Protein Levels

• Low albumin: Poor diet (malnutrition), kidney disease, liver disease, autoimmune disease, uncontrolled diabetes, hyperthyroidism, heart failure