A method of health monitoring, performed on a dried blood sample obtained from a patient said method comprising: a) reconstituting the dried blood sample with a solution; contacting the reconstituted sample to a peptide array, wherein the array comprises a plurality of in-situ synthesized peptides immobilized to pre-determined different locations on a solid support, wherein the in-situ synthesis of the peptides comprises the steps of: b) contacting the reconstituted sample to a peptide array, wherein the array comprises a plurality of in-situ synthesized peptides immobilized to pre-determined different locations on a solid support, wherein the in-situ synthesis of the peptides comprises the steps of: a. adding a first monomer to a pre-determined fraction of locations on the solid support; b. adding a second monomer to a pre-determined fraction of locations on the solid support, wherein the pre-determined fraction of locations for the second monomer includes locations containing the first monomer and locations with no monomer; c. adding a third monomer to a pre-determined fraction of locations on the solid support, wherein the pre-determined fraction of locations for the second monomer includes locations containing the first and second monomer, locations containing the second monomer and locations containing no monomer; and d. repeating steps a-c with a defined set of monomers until the monomers form at least one peptide of a desired average length and the sum of the fractions total is at least 100%; wherein the plurality of different peptides are capable of off-target binding of at least one antibody in the reconstituted dried blood sample; c) measuring the off-target binding of the at least one antibody to the plurality of different peptides in the peptide array to form an immunosignature; and d) identifying a state of health based on the immunosignature, wherein the immunosignature measures changes in binding of the antibody from the reconstituted dried blood sample to the peptide array as compared to a control. a) reconstituting the dried blood sample with a solution; contacting the reconstituted sample to a peptide array, wherein the array comprises a plurality of in-situ synthesized peptides immobilized to pre-determined different locations on a solid support, wherein the in-situ synthesis of the peptides comprises the steps of: b) contacting the reconstituted sample to a peptide array, wherein the array comprises a plurality of in-situ synthesized peptides immobilized to pre-determined different locations on a solid support, wherein the in-situ synthesis of the peptides comprises the steps of: a. adding a first monomer to a pre-determined fraction of locations on the solid support; b. adding a second monomer to a pre-determined fraction of locations on the solid support, wherein the pre-determined fraction of locations for the second monomer includes locations containing the first monomer and locations with no monomer; c. adding a third monomer to a pre-determined fraction of locations on the solid support, wherein the pre-determined fraction of locations for the second monomer includes locations containing the first and second monomer, locations containing the second monomer and locations containing no monomer; and d. repeating steps a-c with a defined set of monomers until the monomers form at least one peptide of a desired average length and the sum of the fractions total is at least 100%; wherein the plurality of different peptides are capable of off-target binding of at least one antibody in the reconstituted dried blood sample; a. adding a first monomer to a pre-determined fraction of locations on the solid support; b. adding a second monomer to a pre-determined fraction of locations on the solid support, wherein the pre-determined fraction of locations for the second monomer includes locations containing the first monomer and locations with no monomer; c. adding a third monomer to a pre-determined fraction of locations on the solid support, wherein the pre-determined fraction of locations for the second monomer includes locations containing the first and second monomer, locations containing the second monomer and locations containing no monomer; and d. repeating steps a-c with a defined set of monomers until the monomers form at least one peptide of a desired average length and the sum of the fractions total is at least 100%; wherein the plurality of different peptides are capable of off-target binding of at least one antibody in the reconstituted dried blood sample; c) measuring the off-target binding of the at least one antibody to the plurality of different peptides in the peptide array to form an immunosignature; and d) identifying a state of health based on the immunosignature, wherein the immunosignature measures changes in binding of the antibody from the reconstituted dried blood sample to the peptide array as compared to a control.