Biopolymer automatic identifying method

A biopolymer automatic identifying method, comprising:

• (a) obtaining a plurality of observed mass values, by subjecting a sample comprised of one or more biopolymers to MS/MS, producing candidate molecules;
• (b) matching at least one of said observed mass values with a theoretical mass value, in a predetermined database of known mass values using a suitably programmed computing device, for candidate molecules, wherein one of said candidate molecules has a high similarity score such that it is thereby identified as an internal reference;
• then
• (c) selecting at least one candidate molecule from (b) that has such a high similarity score using a suitably programmed computing device;
• (d) calibrating said plurality of observed mass values with said internal reference to produce calibrated mass values using a suitably programmed computing device,
• wherein said internal reference is the theoretical mass of the selected candidate molecule or molecules in (c), and
• wherein each of said calibrated mass values is determined by the equation
• Xc=X/(1+(aX+b)), wherein
• Xc is a calibrated mass value,
• X is an observed mass value,
• b=Σ{(M−mM)×(E−mE)}/Σ{(M−mM)2},
• a=mE−bXmM,
• E=(X−M)/M,
• mE=Σ(E)/n, and
• mM=Σ(M)/n,
• wherein M is the theoretical mass value for said candidate molecule and n is the total number of candidate molecules;
• (e) calculating relative error between said calibrated mass value of a candidate molecule in (d) and a theoretical mass value to determine the standard deviation of said relative error using a suitably programmed computing device;
• (f) determining a tolerance of the matching step using said standard deviation (e) and a suitably programmed computing device, wherein said tolerance is determined by the equation
• Tc−K×SEC, wherein K is 1.5 to 3.0;
• optionally,
• (g) repeating steps (b)-(f) using a suitably programmed computing device;
• and then
• (h) comparing said calibrated mass values to said predetermined database, thereby to determine the identity of at least one of said biopolymers using a suitably programmed computing device.