Immunoassay and antibodies for the detection of chromogranin A

An immunoassay method for detection of Chromogranin A or a fragment thereof comprising:

• a) contacting a sample suspected of comprising Chromogranin A with
• (i) a first antibody specific for Chromogranin A, and
• (ii) a second antibody specific for Chromogranin A,
• under conditions allowing for formation of a ternary complex between Chromogranin A and the two antibodies, wherein:
• the first antibody is produced by the hybridoma cell line 537/H2 deposited as DSM ACC3231 or is an antigen-binding fragment of the antibody produced by the hybridoma cell line 537/H2 deposited as DSM ACC3231;
• or
• the second antibody is produced by the hybridoma cell line 541/E2 deposited as DSM ACC3232 or is an antigen-binding fragment of the antibody produced by the hybridoma cell line 541/E2 deposited as DSM ACC3232;
• or
• the first antibody is produced by the hybridoma cell line 537/H2 deposited as DSM ACC3231 or is an antigen-binding fragment of the antibody produced by the hybridoma cell line 537/H2 deposited as DSM ACC3231, and the second antibody is produced by the hybridoma cell line 541/E2 deposited as DSM ACC3232 or is an antigen-binding fragment of the antibody produced by the hybridoma cell line 541/E2 deposited as DSM ACC3232;
• and
• b) detecting the binding of the first and second antibodies to Chromogranin A.