Which lipoprotein is described as floating prebetalipoprotein with high cholesterol content?

• A. IDL
• B. B-VLDL
• C. Lp(a)
• D. LpX

Answer: (B)

Lipoproteins are classified by how they migrate in electrophoresis and what lipids they carry. The term prebetalipoprotein refers to VLDL because it moves in front of the beta region on electrophoresis (prebeta region). This particle is relatively rich in cholesterol as it sits upstream of LDL in the metabolism pathway, often described as a beta-VLDL form that is effectively the floating prebetalipoprotein with higher cholesterol content.

Therefore, the lipoprotein described fits the B-VLDL description. The other options don’t match this prebeta, cholesterol-rich VLDL description: IDL is a VLDL/LDL remnant, Lp(a) is an LDL-like particle with apolipoprotein(a), and LpX is an abnormal cholesterol/phospholipid-rich particle seen in cholestasis rather than prebetalipoprotein.