Patent ID: 8911951

Claim:
A method for diagnosing lung cancer in a subject, the method comprising: (i) isolating and concentrating glycoproteins from a biological sample of the subject by using a multi-lectin affinity column packed with ConA (concanavalinA), LCH (lentil lectin), GNA (snowdrop lectin, WGA (wheat germ agglutinin), SNA (elderberry lectin), MAL ( Maackia amurensis lectin), AIL (Jacalin), and PNA (peanut agglutinin); (ii) denaturing the isolated and concentrated glycoproteins in a buffer containing mercaptoethanol and octyl beta-D-glucopyranoside; (iii) deglycosylating the denatured glycoproteins in a reaction buffer comprising peptide-N-glycosidase F (PNGase F); (iv) separating the deglycosylated glycoproteins using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE); (v) transferring the SDS-PAGE separated glycoproteins onto a Western blot membrane; (vi) treating the Western blot membrane containing the transferred glycoproteins with a primary antibody and a secondary antibody to form an antigen-antibody complex wherein the glycoproteins from the biological sample comprise a plasma kallikrein fragment (KLKB1) which comprises SEQ. ID NO: 1 and is present on the Western blot membrane, wherein the primary antibody is an anti-KLKB1 antibody that binds an epitope within amino acid residues of 361-400 of the plasma kallikrein fragment, and the secondary antibody binds the primary antibody; and (vii) diagnosing lung cancer in the subject when a 15-20 kDa mass fragment band on the Western blot membrane which corresponds to the plasma kallikrein fragment is detected at a level higher than a normal level found in a healthy person.