Table 1.

Constituents of serum [Adapted from [112]].

	Range of		Range of
Constituent	concentration	Constituent	concentrationa
Proteins and polypeptides	40–80 mg/mL	Polyamines:	0.1–1.0 μM
Albumin	20–50 mg/mL	Putrescine, Spermidine
Fetuinb	10–20 mg/mL
Fibronectin	1.0–10 μg/mL	Urea	170–300 μg/mL
Globulins	1.0–15 mg/mL
Protease inhibitors:	0.5–2.5 mg/mL	Inorganics	0.14–0.16 M
αl-antitrypsin,		Calcium	4.0–7.0 mM
α2-macroglobulin		Chlorides	100 μM
Transferrin	2.0–4.0 mg/mL	Iron	10–50 μM
		Potassium	5.0–15 mM
Growth factors:		Phosphate	2.0–5.0 mM
EGF, PDGF, IGF1 and 2,	1.0–100 ng/mL	Selenium	0.01 μM
FGF, IL-1, IL-6		Sodium	135–155 mM
		Zinc	0.1–1.0 μM
Amino acids	0.01–1.0 μM
		Hormones	0.1–200 nM
Lipids	2.0–10 mg/mL	Hydrocortisone	10–200 nM
Cholesterol	10 μM	Insulin	1.0–100 ng/mL
Fatty acids	0.1–1.0 μM	Triiodothyronine	20 nM
Linoleic acid	0.01–0.1 μM	Thyroxine	100 nM
Phospholipids	0.7–3.0 mg/mL
		Vitamins	0.01–10 μg/mL
Carbohydrates	1.0-2.0 mg/mL	Vitamin A	10–100 ng/mL
Glucose	0.6–1.2 mg/mL	Folate	5.0–20 ng/mL
Hexosamine	0.6–1.2 mg/mL
Lactic acid	0.5–2.0 mg/mL
Pyruvic acid	2.0–10 μg/mL

^aThe range of concentrations is approximate and is intended to convey only the order of magnitude.

^bIn fetal serum only.