S100B ELISA

S100 is a 20 kDa protein belonging to the
S100/calmodulin/troponin C superfamily of EF-hand
calcium-binding proteins. S100 was originally isolated
from human brain and considered a glial-cell specific
protein (1). Today, 20 monomers of the S100 family
have been identified based on structural and
functional similarities (2,3). Most of the S100 proteins
exist as dimers and are expressed in a cell-specific
manner. Two of the S100 monomers, designated
S100α and S100β (4) are highly conserved between
species and are found as homo- (ββ) and
heterodimers (αβ) in central nervous system glial
cells and in certain peripheral cells eg. Schwann
cells, melanocytes, adipocytes, and chondrocytes (5).
S100αβ and S100ββ are also present in malignant
tissues, most notably in melanoma and to a lesser
extent in glioma, thyroid cell carcinoma and renal cell
carcinoma (2). Determination of S100B (like S100αβ
and S100ββ units) in serum has been shown to be
clinically useful for prognosis and treatment
monitoring of patients diagnosed with malignant
melanoma (6-9). Studies also suggest that S100B
may be useful in the management of patients
with brain damage from eg. traumatic head injury,
perinatal asphyxia, cardiac arrest, cardiac surgery
and stroke (10-13).