Serology Slides Marchionne
Unit 4: Serology - Blood Serum Diagnostics
Overview
Study of blood immunology focusing on antibody-antigen interactions.
Essential for understanding blood typing and diagnosis through blood serum.
Serology Vocabulary
Agglutination: Clumping of cells in response to antibodies.
Allele: Variants of a gene at a specific locus on a chromosome.
Antibody: Protein produced by the immune system to identify and neutralize antigens.
Antigen: A substance that induces an immune response; usually a protein on the surface of pathogens or cells.
Antiserum: Serum containing specific antibodies for laboratory tests.
Chromosome: Structure in cells containing DNA; humans have 46.
Cystic fibrosis: Genetic disorder affecting the respiratory and digestive systems.
Dominant trait: Genetic trait that expresses itself even when only one copy is present.
DNA: Molecule containing the genetic information of organisms.
Egg: Female reproductive cell.
Enzyme: Protein that accelerates biochemical reactions.
Erythrocyte: Red blood cell responsible for oxygen transport.
Erythroblastosis fetalis: Condition in newborns due to Rh incompatibility.
Gene: Unit of heredity; segment of DNA.
Genotype: Genetic constitution of an individual.
Hemoglobin: Protein in red blood cells that carries oxygen.
Heterozygous: Having two different alleles at a locus.
Homozygous: Having two identical alleles at a locus.
Leukocyte: White blood cell that fights infection.
Locus: Specific location of a gene on a chromosome.
Malaria: Disease caused by Plasmodium parasites, transmitted by mosquitoes.
Phenotype: Observable characteristics of an organism.
Plasma: Liquid component of blood, accounting for 55%.
Precipitin: Antibody that forms a precipitate with its corresponding antigen.
Recessive trait: Trait that is expressed only in homozygous conditions.
Serology: Study of blood serum, especially regarding immune responses.
Serum: Liquid part of blood after clotting proteins have been removed.
Sickle Cell: Genetic disorder caused by abnormal hemoglobin.
Spermatid: Male reproductive cell.
Thalassemia: Genetic blood disorder affecting hemoglobin production.
X Chromosome: One of the two sex chromosomes, contributing genes such as those for color vision.
Y Chromosome: Male sex chromosome responsible for male traits.
Zygote: Fertilized egg forming after the union of sperm and egg.
Part 1: Blood
Introduction
In 1901, Karl Landsteiner discovered blood typing.
Received a Nobel Prize 29 years later, following earlier transfusion failures.
Developed the A-B-O blood system; more than 100 other blood factors discovered (e.g., Rh factor).
What is Blood?
Composed of:
Blood Cells: Erythrocytes (RBCs), leukocytes (WBCs), platelets.
Plasma: Fluid portion of blood, containing water, ions, proteins, nutrients, waste products, and gases.
Components of Blood
Erythrocytes: Carry oxygen and carbon dioxide.
Leukocytes: Combat infections.
Platelets: Assist in clotting.
Plasma: The fluid component that contains serum, minerals, proteins, and other substances.
Blood Coagulation
Cascade reaction leading to clot formation; a challenge to Darwin's theory of evolution suggesting complexity in biological systems.
Blood Clot (Thrombus)
Formation through the accumulation of blood cells and platelets, blocking arteries (e.g., in heart disease).
Clarification of Terms
Agglutination = Coagulation = Clotting: Clumping of cells together (e.g., due to antibodies).
Precipitation: Formation of visible clumps from a solution, significant in serological tests.
Antigens & Antibodies
Antigens are protein structures on red blood cells recognized by the immune system.
Each antigen matches a specific antibody leading to agglutination.
Blood Typing
Blood consists of different antigens resulting in various blood types (A, B, AB, O) differentiated by their antibodies.
Rh Factor: Determines positive or negative blood type based on presence of Rh antigen.
Part 2: Immunoassay Techniques & Blood Stains
Detection of Drugs
Specific antigen-antibody reactions aid in drug detection in blood and urine.
Immunoassays are rapid tests often needing confirmation for accuracy.
Preliminary Color Tests
Kastle-Meyer test: Pink color indicates blood presence when mixed with H₂O₂.
Hemastix strips: Green color change indicates blood presence.
Luminol & Bluestar
Luminol: Detects blood through light emission in dark conditions.
Bluestar: Similar to luminol but more visible, does not require darkness.
Precipitin Test
Used to identify if blood is of human or animal origin, indicating specific antigens.
Gel Diffusion
Type of precipitin test where blood and antibodies form a precipitant in a gel.
Part 3: Principles of Heredity
Genes and Chromosomes
Gene: Basic unit of heredity found on chromosomes.
Humans possess 46 chromosomes in 23 pairs, including sex chromosomes (XX for female, XY for male).
Alleles
Positioned at corresponding loci and can have multiple forms affecting traits.
Homozygous: Two identical alleles; Heterozygous: two different alleles.
Genotypes and Phenotypes
Genotype: Genetic constitution; Phenotype: observable trait resulting from the genotype.
Blood Type Inheritance
Blood type alleles A, B, and O located on chromosome 9 leading to various genotypes.
Punnett squares are used to predict offspring blood types based on parental genotypes.
Paternity Testing
Blood type testing can provide evidence for paternity cases along with DNA testing for higher accuracy.
Blood and Genetic Disorders
Erythroblastosis Fetalis
Occurs when an Rh- mother has an Rh+ child, leading to fetal complications in subsequent pregnancies.
Sickle Cell Anemia
Caused by a mutation in hemoglobin, affecting oxygen transport and red blood cell shape.
Thalassemia
Genetic disorder impacting hemoglobin production, offering resistance to malaria.
Cystic Fibrosis
Caused by mutations in the CFTR gene, leading to thick mucus production affecting respiratory health.