Laboratory Procedures and Diagnostics Flashcards

What does an elevated erythrocyte sedimentation rate (ESR) indicate?

Answer: Nonspecific inflammation or infection in the body

ESR is a nonspecific marker of inflammation; an elevated rate indicates the presence of inflammatory, infectious, or autoimmune conditions.

Which blood cell type is primarily responsible for fighting bacterial infections?

Answer: Neutrophils

Neutrophils are the most abundant white blood cells and serve as the primary defense against bacterial infections through phagocytosis.

When collecting a throat swab for strep culture, which area should be swabbed?

Answer: The posterior pharynx and tonsillar areas

A throat culture requires swabbing the posterior pharynx and tonsillar areas where Group A Streptococcus colonizes, while avoiding the tongue and cheeks.

What is a differential white blood cell count used to evaluate?

Answer: The proportion of each type of white blood cell in a sample

A differential WBC count identifies the percentage of each leukocyte type (neutrophils, lymphocytes, monocytes, eosinophils, basophils), helping diagnose infections and hematologic disorders.

Which chain-of-custody procedure is critical when handling specimens for forensic or drug testing purposes?

Answer: Documenting specimen handling from collection to disposal with signatures at each transfer

Chain of custody requires documented accountability for specimen handling at every step to ensure the specimen's integrity and admissibility as legal evidence.

A urine specimen has a specific gravity of 1.030. What does this indicate?

Answer: The urine is highly concentrated

Normal urine specific gravity ranges from 1.001-1.030; a value of 1.030 indicates highly concentrated urine, suggesting dehydration.