Plasma Proteins - Globulins and Protein Electrophoresis (not finished)

4%

It’s an important clotting factor It’s converted into fibrin during the clotting process

All non albumin proteins in blood except fibrinogen

Total globulins = Total protein - albumin

The total globulin fraction along with the albumin can be used to differentiate the causes of hypo and hyper proteinaemia

Males have a slightly higher total globulin than females Children and neonates have slightly lower total globulin than adults Some problems with supine measurements as with albumin and total protein

Gamma globulins Enzymes Carrier/transport proteins

This is done by serum electrophoresis

It separates blood proteins according to size and charge

Albumin Alpha-globulins Beta-globulins Gamma globulins

Made predominantly by the liver They are increased during acute phase protein synthesis which occurs 2-5 days after injury to cells

They are produced by plasma cells

Dehydration Immune response Myeloma

Liver disease (normal to low) Renal disease Salt retention syndromes Intestinal malabsorption Burns Immune deficiency

A test that roughly quantitates the various protein fractions in serum

Blood serum is placed on specially treated support and exposed to an electric current. The various proteins migrate (move on the support) to form bands that indicate the relative proportion of each protein fraction. Individual proteins, with the exception of albumin, are not usually measured. However, protein fractions or groups ARE measured. The levels of protein fractions can be roughly measured by measuring the total serum protein and multiplying by the relative percentage of each component protein fraction.

The procedure consists of applying a drop of serum to a support medium, such as a sheet of cellulose acetate or agarose that is soaked in a buffer in a chamber. In this alkaline environment, all the proteins have a negative charge but each has a different magnitude. As an electric current is passed through the medium, the proteins migrate toward the positively charged anode and are separated because of their charge differences into several bands on the medium. After a set period, the cellulose acetate sheet with the separated proteins is removed, fixed, cleared, and the proteins stained. The staining reveals a series of bands at different positions; the width and density of the bands depends on the amount of proteins with that particular electrophoretic mobility

Albumin a1-globulin a2- globulin B-globulin y-globulin

A method of separating proteins based upon the charge and molecular weight of the protein. Most proteins are negatively charged and will move toward a positive electrode (anode). The amounts and locations of the separated proteins are represented graphically. The concentration of each protein peak can be determined by calculating the area under the curve on the electrophoretogram

SPE is an important screening test for serum protein abnormalities. Samples are applied to a gel prior to electrophoresis and staining. Sera showing abnormal results should be further investigated by Immuno-Fixation Electrophoresis [IFE]. Serum sample is preferred to Plasma sample Serum sample contains all Plasma proteins minus clotting agents [Notably Fibrinogen] Haemolysed samples can cause problems

Narrow peak closest to the anode, has a strong negative charge

a1-acid glycoprotein a1- antitrypsin High density lipoprotein

Haptoglobin - largest portion of this peak, binds free Hb Serum amyloid A a2- macroglobulin - proteinase inhibitor Caeruloplasmin Very low density lipoprotein (VLDL) Low density lipoproteion

fibrinogen C reactive protein – activates complement protein C complement amyloid A ferritin LDL IgM and IgA may bridge the β and γ regions