Biochemistry Final Comprehensive Review

Albumin

3.5-5.5 g/dL

Alkaline Phosphate

36-92 U/L

Aminotransferase, Alanine (ALT)

0-35 U/L

Aminotransferase, Aspartate (AST)

0-35 U/L

Amylase

0-130 U/L

Bicarbonate

23-28 meq/L

(23-28 mmol/L)

Bilirubin, Total

0.3-1.2 mg/dL

Bilirubin, Direct (Conjugated)

0-0.3 mg/dL

pH

7.38-7.44

PCO2

35-45 mmHg

PO2

80-100 mmHg

Blood Urea Nitrogen (BUN)

8-20 mg/dL

Calcium

9-10.5 mg/dL

Carbon Dioxide Content, Serum

23-28 meq/L

Chloride

98-106 meq/L

Cholesterol, Total

<200 mg/dL

Low-Density Lipoprotein (LDL)

<130 mg/dL

High-Density Lipoprotein (HDL)

>40 mg/dL

Triglyceride

<250 mg/dL

Creatinine

0.7-1.3 mg/dL

Glucose

70-100 mg/dL

γ-Glutamyltransferase

0-30 U/L

IgG

640-1430 mg/dL

IgA

70-300 mg/dL

IgM

20-140 mg/dL

IgD

<8 mg/dL

IgE

0.01-0.04 mg/dL

Ferritin

15-200 ng/mL

Iron

60 - 160 µg/dL

Transferrin saturation (TSAT)

20-50%

Lactate dehydrogenase (LDH)

60-100 U/L

Lead

<5 ug/dL

Potassium

3.5-5.0 mEq/L

Osmolality

275-295 mosm/kg H2O

Phosphorus

3.0-4.5 mg/dL

Protein, Total

6.0-7.8 g/dL

Protein, Globulins

2.5-3.5 g/dL

Sodium

136-145 meq/L

Uric acid

2.5-8.0 mg/dL

Henderson-Hasselbalch Equation

Anion Gap Equation

Osmolality Equation

Transferrin Saturation Equation

Creatinine Clearance Equation

Coefficient of Variation (CV) Equation

Standard Deviation Formula

Total Cholesterol Equation

VLDL Equation

Friedewald formula

Formula for Calculating Absorbance given T%

The linear relationship between absorbance and concentration of an absorbing species.

Beer-Lambert Law (Beer's Law)

Beer's Law

What is used to verify the acceptability of new methods prior to reporting patient results?

Method evaluation

What is the first step of method evaluation?

Determine imprecision and inaccuracy

What is the foundation for monitoring performance (known as QC)?

Descriptive statistics

What are the three measures of center?

Mean, median, mode

What is the most commonly used measure of center and often called the average?

Mean

What is the middle point and is often used with skewed data so that outliers do not significantly affect the calculation?

Median

What is the measure of center that is rarely used and is the most frequently occurring value in a data set?

Mode

What is the term for how data is distributed?

Spread

What is the term for distribution of a data set?

Shape

What is the difference between test and reference method results?

Error

What is the term for when the mean, median, and mode are identical and distribution is symmetrical?

Gaussian or bell curve

What is the total area under a Gaussian distribution?- What percent falls within 1 SD?- What percent falls within 2 SD?- What percent falls within 3 SD?

1.0 or 100%

68.3%

95.4%

99.7%

What involves measuring patient specimens by both existing reference and new test methods?

Comparison of methods experiment

What type of analysis provides objective measures of location and dispersion of line?

Linear regression

Which error is present in all measurements and can be either positive or negative?

Random error

What error can result from factors including instrument, operator, reagent, or environmental variation?

Random error

Which error influences observations consistently in one direction?

Systematic error

What type of systematic error is in the sample direction and magnitude; magnitude of change is constant and not dependent on the amount of analyte?

Constant error

What type of systematic error is where the magnitude changes as a percent of the analyte present, error dependent on analyte concentration?

Proportional error

What is a random error plus systematic error?

Total error

What are the descriptive statistics of groups of paired observations?

1. Comparison of methods experiment

2. Linear regression

3. Types of errors

What is used to draw conclusions regarding means or standard deviations of two sets of data?

Inferential statistics

Regulators

What are the two primary government agencies that influence laboratory testing methods?

CMS & FDA

CLIA Regulations for method validation for Nonwaived FDA-Approved tests

1. Demonstrate test performance comparble to that established by manufacturer

a. Accuracy

b. Precision

c. Reportable range

2. Verify reference values appropriate for patient population

CLIA Regulations for method validation for Nonwaived FDA-Approved tests modified or developed by laboratory

1. Determine

a. Accuracy

b. Precision

c. Analytic sensitivity

d. Analytic specificity

e. Reportable range of test results

f. Reference ranges

g. Other performance characteristics

h. Calibration and control procedures

What is new methods selected to reduce costs, improve quality, satisfy clients, or improve efficiency called?

Method selection

What is the dispersion of repeated measurements about the mean due to analytic error?

Imprecision

What is the term for how close the measured value is to the true value due to systematic error?

Inaccuracy

Measurement imprecision

1. Estimates random errors associated with test methods

2. Detects any problems affecting its reproducibility

3. Should be performed over a 10 to 20 day period

Imprecision or Inaccuracy

Imprecision

Imprecision or Inaccuracy

Inaccuracy

How is precision best measured?

Coefficient of Variation

What are the estimations of inaccuracy?

1. Recovery studies

2. Interference studies

3. Comparison of method studies

What shows whether a method is able to accurately measure an analyte?

Recovery studies

What determines if specific compounds affect accurate determination of analyte concentrations?

Interference studies

What examines patient samples by method being evaluated (test) with a reference method?

Comparison of Methods studies

What are methodologies used in past to estimate medically allowable error?

Allowable Analytic Error

Who published error limits allowable by federally mandated proficiency testing?

CLIA

What is the ability of a method to detect small quantities or small changes in concentration of an analyte?

Analytic sensitivity

What is the ability of a method to detect only the analyte it is designed to determine?

Analytic specificity

What is the proportion of people with disease who test positive?

Clinical sensitivity

What is the ability of a test to correctly identify the absence of a given disease or condition?

Diagnostic specificity

What is the ability of a test to detect a given disease or condition?

Diagnostic sensitivity

What is positive predictive value?

Chance of an individual having a given disease if the test is abnormal

What is negative predictive value?

Chance an individual does not have a disease if the test is within the reference interval

What is the formula for specificity?

TN/(TN + FP)

What is the formula for positive predictive value?

TP/(TP+FP)