Submit Article |Resources | Link to us | Sitemap | Search | Language
Back to Home
Home >> Biotechnology in Medicine >> Autoantibody Fingerprinting Using Dipsticks
Back to Home

Autoantibody Fingerprinting Using Dipsticks - Autoantibodies that react with cellular components occur in high frequency in patients with systemic rheumatic diseases. However, a novel class of autoantibodies that react with cellular components has now been identified in normal humans and other animal species.

Unlike the disease associated autoantibodies, that are restricted in number, these human autoantibodies increase in number from birth upto the age of two years and then remain constant for decades, if not lifelong.

The complement of these autoantibodies present in an individual is unique and for this reason they have been named individual specific (IS) autoantibodies. These IS autoantibodies when physically separated comprise an antibody fingerprint that can serve to identify people just like DNA fingerprints discussed above. For these autoantibody fingerprints, body fluids such as blood, semen, tears, saliva, and perspiration can be used.

The advantages of autoantibody fingerprinting over DNA fingerprinting include the following:
(i) sensitivity (less than 10 It blood needed);
(ii) rapidity (only few- hours needed; no DNA extraction required, which may take time);
(iii) simplicity (no equipment required);
(iv) cost effectiveness;
(v) portability;
(vi) autoantibody fingerprints though are similar in the newborn child and the mother, can distinguish between genetically identical individuals like identical twins which can not be distinguished through DNA fingerprinting.

The autoantibody fingerprinting protocol involves (a) preparation of antigen and (b) antibody fingerprint assay. Following steps are involved:

(i) A panel of antigens is prepared from an extract of human cells (e.g: HeLa cells) cultured in vitro; the antigens are first separated by molecular mass with denaturing polyacrylamide gel electrophoresis (SDS­PAGE);
(ii) the antigens are then transferred electrophoretically to a nylon membrane;
(iii) unbound sites on the membrane are blocked with the help of a blocking agent;
(iv) the membranes are cut into strips called dipsticks, which are
(v) incubated with dilutions of sera or plasma for 1 hour,

(vi) washed with buffer,
(vii) incubated in detector molecule (1 μ Ci/assay of 1251 protein, which binds to the Fc protein of human IgG in the immune complex formed) for 1 hour;
(viii) rewashed and dried and
(ix) finally used for autoradiography on X-ray film. or scanned with a gamma scanner or an optical scanner. The results obtained can be utilized for the identification of individuals (humans, dogs, mice, cows, horses, rabbits, etc.).

 
Submit Article |Resources | Link to us | Sitemap | Search | Language
English|Français|Español|Deutsch|Italiano|Portugues|Japanese|Korean|Sim-Chinese| Language