Lab Methods Flashcards
Y-axis of Receiver Operating Characteristic Curve
Sensitivity
X-axis of Receiver Operating Characteristic Curve
False positive rate (1 - specificity)
Receiver Operating Characteristic Curve is a plot of these values
Likelihood ratios
Type of reference range that uses a Gaussian distribution and +/- 2 standard deviations from the mean
Default reference range
Type of reference range where the values may lie on a Gaussian distribution, but many values within the central 95% are not desirable
Uses recommendations based on research and clinical experience to establish “desired values”
Prognosis/treatment derived range
Cholesterol and blood pressure use this type of reference range
Prognosis/treatment derived range
Type of reference range that determines a value that, when exceeded, indicates disease
For metabolites that are not normally found in the blood
Threshold value
Cardiac markers and drugs of abuse screens utilize this type of reference range
threshold value
Type of reference range that establishes a “therapeutic window” for drug levels
Established by experimentation and clinical data to maximize drug effectiveness and minimize toxicity
Therapeutic drug range
Screening tests often intentionally have a high false _____ rate
False positive
goal is to capture all possible disease
Which has a high specificity: screening or confirmatory tests?
Confirmatory test
Which has a high sensitivity: screening or confirmatory tests?
Screening test
formula that links test accuracy with likelihood of disease (pre-test probability) to determine post-test probability
Bayes Theorem
Accuracy in the Bayes Theorem refers to these 2 values
Sensitivity and specificity
Likelihood / pre-test probability in the Bayes Theorem refers to this value
Prevalence
When ordering tests, you should select order tests first with lower to higher _____?
Specificity
Most common type of lab test errors
Pre-analytical
Least common type of lab test errors
Analytical
Second most common type of lab test errors
Post-analytical
2 interfering substances in spectrophotometry
Bilirubin and lipids
Source of error in ELISA and Latex Agglutination where Analyte concentration is so high that it binds all sites on both capture Ab and Detector Ab
Gives falsely low measurement
Hook Effect
Anti-animal antibodies in the patient during an ELISA gives falsely high or low measurement?
High
Hook effect in ELISA gives falsely high or low measurement?
Low
Clinical laboratory test where presence of analyte results in clumping of Ab coated beads
Detected as a change in turbidity
Latex Agglutination
Clinical lab test used for drug detection/measurement, cells (blood types), serologic tests
Latex Agglutination
Tissue sampling technique: examining cells or cell clusters which are largely detached from supporting tissue
Cytology
Type of cytology involving sampling cells which are detached from a surface
Exfoliative cytology
Pleural fluid aspiration, pap test, bronchoalveolar lavage, and bile duct brushing are examples of this tissue sampling technique
Exfoliative cytology
Analyzing Lung mass via EBUS, thyroid mass via palpation or ultrasound, pancreas mass via EUS involves this tissue sampling technique
Fine-needle aspriation
Fine-needle aspiration is a subtype of this tissue sampling technique
Cytology
Tissue sampling technique: sampling a portion of a lesion; removing entire lesion with limited tissue amount (e.g. skin)
Biopsy
Type of biopsy where a cylindrical portion of tissue is removed
Core biopsy
Type of biopsy where part of a lesion is surgically sampled
Incisional biopsy
Type of biospy where the entire lesion is removed, but not entire organ/region
Excisional biopsy
Type of biopsy where forceps/pincer tool removes small portion of mucosal surface
Endoscopic biopsy
Tissue sampling technique: removing entire organ, region of organ, or groups of organ
Usually done with curative intent
Ex: hemicolectomy, mastectomy, lumpectomy
Resection
4 steps in surgical pathology tissue sample processing for histological examination
- Formalin fixative (cross links proteins and stabilizes tissues)
- Ethanol dehydration
- Xylene
- Paraffin wax (allows for preservation and thin slicing)
Step in tissue sample processing for histological examination that cross links proteins and stabilizes tissue
Formalin fixative
Used in tissue sample processing for histological examination for dehydration step
Ethanol
Histochemical stain that stains acidic tissues, is eosinophilic, and appears pink/orange
Eosin
Color of eosin stain
Pink/orange
Eosin stains this type of tissues
Acidic
Smooth muscle and collagen are stained by this in H&E stains
Eosin
Blue stain that stains basic tissues; is basophilic
Hematoxylin
Hematoxylin stain is this color
Blue
Nuclei are stained by this in an H&E stain
Hematoxylin
Are basophilic
Compound that is blue on trichrome stain
Collagen
Collagen is this color on trichrome stain
Blue
Collagen is blue on this stain
Trichrome stain
Elastin stains this color on elastic stain
Black
Smooth muscle, collagen, and elastic are basophilic or eosinophilic?
Eosinophilic
Mucus is stained by this
PAS
Amyloid is stained with this
Congo red
Fungus are stained by this
PAS
PAS stains these
Glycated proteins, mucus, fungi
AFB stain these
Mycobacteria
Marker of epithelial differentiation
Cytokeratin
Cytokeratin is a marker of this
Epithelium
Carcinoma is this type of malignancy
Epithelial
(so all is keratin positive)
Stains nervous, adipose, chondrocytes (cartilage), melanocytic
S100
S100 stains these types of tissue
Nervous, adipose, chondrocytes (cartilage)
Desmin stains this
Muscle
Muscle is stained by this
Desmin
Marker of glial differentiation
GFAP
Marker of hematologic differentiation
CD45
