Quick Review Cards for Medical Laboratory Science

Examples of Preanalytical Factors That

May Affect Chemistry Results continued

Clinical Chemistry Review 71

Inadequate centrifugation

Recentrifugation of primary tubes

Delay in separating serum/plasma (unless gel
tube is used)

Storage temperature

FACTOR EFFECT

Poor barrier formation in gel tubes can result in ↑K+, LD, AST, iron, phosphorus

Hemolysis, ↑K+

↑ammonia, lactic acid, K+, Mg2+, LD

↓glucose (unless collected in fluoride)

↓at RT: glucose (unless collected in fluoride)

↑at RT: lactic acid, ammonia

↓at 4ºC: LD

↑at 4ºC: ALP