Which has least density?

Classification as per hydrated density: Pure fat is less dense than water. As the propoion of lipid to protein in lipoprotein complexes increases |, the density of the macro-molecule decreases|. Use of the above propey has been made in separating various lipoproteins in plasma by ultracentrifugation. Svedberg units of floatation (Sf unit): The rate at which each lipoprotein floats through a solution of NaCl (Sp.gr. 1.063) is expressed as "Svedberg" units of floatation (Sf).Sf unit: One Sf unit is equal to 10-13 cm/S/dyne/g at 26degC. Gofman and colleagues (1954) separated lipoproteins by ultracentrifugation into four major density classes:Chylomicrons: Density lowest-floatsVery low-density lipoproteins (VLDL or VLDLP)Low-density lipoproteins (LDL), andHigh Density Lipoproteins (HDL): settles below.LDL: It has been fuher divided into LDL 1, IDL (intermediate density lipoprotein) and LDL-2HDL: It has been fuher separated into HDL-1 (this fraction is quantitatively insignificant), HDL-2 and HDL-3. Recently HDL c has been described.Ref: Textbook of Medical Biochemistry 8th Edition Dr (Brig) MN Chatterjea, Rana Shinde, page no: 444