Table 3. Protein mass calibration standards
| Name | Source | Average mass [M+H]+ (Da) |
Sigma product number | SWISS-PROT reference |
| Cytochrome c | Tuna | 12,043.6 | C2011 | CYC_KATPE |
| Cytochrome c | Bovine | 12,232.0 | C3131 | CYC_BOVIN |
| Cytochrome c | Equine | 12,361.2 | C7752 | CYC_HORSE |
| Ribonuclease A | Bovine | 13,683.4 | R5500 | RNP_BOVIN |
| α-Lactalbumin | Human | 14,071.1 | L7269 | LCA_HUMAN |
| α-Lactalbumin | Bovine | 14,179.1 | L6010 | LCA_BOVIN |
| Lysozyme c | Chicken egg | 14,306.1 | L6876 | LYC_CHICK |
| Hemoglobin α-chain | Human | 15,127.3 | G5890 | HBA_HUMAN |
| Hemoglobin β-chain | Human | 15,868.7 | G5890 | HBB_HUMAN |
| Apomyoglobin | Equine | 16,952.5 | A8673 | MYG_HORSE |
| β-Lactoglobulin B | Bovine | 18,278.2 | L8005 | LACB_BOVIN |
| β-Lactoglobulin A | Bovine | 18,364.3 | L7880 | LACB_BOVIN |
| Trypsin inhibitor, α-chain | Soybean | 20,037.6 | T9003 | ITRB_SOYBN |
| Trypsin inhibitor, β-chain | Soybean | 20,091.7 | T9003 | ITRA_SOYBN |
| Trypsin inhibitor, χ-chain | Soybean | 20,163.8 | T9003 | ITRA_SOYBN |
| Growth hormone | Human | 22,126.2 | S4776 | SOMA_HUMAN |
| Trypsinogen | Bovine | 23,982.0 | T1143 | TRYP_BOVIN |
| Chymotrypsinogen A | Bovine | 25,657.1 | C4879 | CTRA_BOVIN |
| Aldolase | Rabbit | 39,204.7 | A7145 | ALFA_RABIT |
| Pepsinogen | Porcine | 39,607.9 | P4656 | PEPA_PIG |
| Alcohol dehydrogenase, S | Equine | 39,712.4 | A6128 | ADHS_HORSE |
| Alcohol dehydrogenase, E | Equine | 39,833.4 | A6128 | ADHE_HORSE |
| Ovalbumin | Chicken | 44,401.0 | A2512 | OVAL_CHICK |
| Glucose-6-phosphate dehydrogenase | Yeast | 57,433.5 | G4134 | G6PD_YEAST |
| Albumin | Bovine | 66,431.0 | A0281 | ALBU_BOVIN |
| Albumin | Human | 66,439.2 | A3782 | ALBU_HUMAN |
| Urease | Jack Bean | 90,762.9 | U0376 | UREA_CANEN |
| Phosphorylase B | Rabbit | 97,219.5 | P6635 | PHS2_RABIT |
| Albumin dimer | Bovine | 132,859.0 | A9039 | ALBU_BOVIN |










