Comprehensive Medical Laboratory Techniques and Pathology Review

QC

Ensures accuracy and precision.

Westgard Rules

Set of rules for interpreting quality control data.

12s Rule

One control outside 2 SD, warning only, don't reject yet.

13s Rule

One control outside 3 SD, random or systematic, reject run.

22s Rule

Two consecutive controls outside 2 SD on same side, systematic, reject run.

R4s Rule

One control +2 SD and one -2 SD, random, reject run.

41s Rule

Four consecutive controls outside 1 SD on same side, systematic, reject run.

10x Rule

Ten results above or below mean, shift/trend, reject run.

Whole blood

Plasma + cells, collected with anticoagulant.

Serum

Liquid portion after clotting (no fibrinogen).

Plasma

Liquid portion before clotting - has fibrinogen.

Urine specimen

Needs to be delivered to lab within 1 hour or refrigerated.

Red tube

No anticoagulant, serum tests, chemistry.

Gold/SST tube

Clot activator, serum separation.

Light blue tube

Sodium citrate, coagulation tests (PT, PTT).

Light green tube

Lithium heparin, chemistry tests (STAT).

Dark green tube

Sodium heparin, chemistry tests (STAT).

Lavender tube

EDTA, hematology.

Pink tube

EDTA, blood bank.

Gray tube

Sodium fluoride/potassium oxalate, glucose preservation, lactate.

Hematology

Analyzes blood cells.

Clinical chemistry

Includes metabolic panels: BMP, CMP, electrolytes, glucose, liver enzymes.

Microbiology

Involves microscopy and culture.

Immunology

Serology, infective disease testing.

Immunohematology

Blood cross matching.

Bacteria

Cell type: prokaryotic, size: medium, reproduction: binary fission, treatment: antibiotics.

Virus

Cell type: not a cell, size: smallest, reproduction: needs host cell, treatment: antivirals.

Fungi

Cell type: eukaryotic, size: largest, reproduction: spores, budding, treatment: antifungal.

RBC Surface Antigens

A, B, AB, O antigens; Rh (D antigen) determines + or -.

Type O

Anti-A & anti-B (universal donor).

Serum vs. Plasma

Serum: no clotting factors (fibrinogen removed); Plasma: has clotting factors.

Metabolic syndrome

Requires 3/5: abdominal obesity, high triglycerides, low HDL, hypertension, high fasting glucose/insulin resistance.

IgG

Crosses placenta, secondary immune response. Seen in chronic and past infections.

IgM

First responder, ABO antibodies.

IgA

Found on mucosal surfaces.

IgE

Involved in allergies and parasites.

IgD

B-cell receptor.

Wright-Giemsa stain

Used for blood smears, WBC morphology.

Gram stain

Used for bacteria classification.

Acid-fast stain

Used for mycobacteria.

PAS stain

Used for fungi, carbohydrates.

Lactophenol cotton blue

Used for fungal structures.

India ink

Used for cryptococcus in CSF.

Prussian blue stain

Used for iron.