Shop Lyophilized Controls

Compare
    ,for, Item ID-
  • #1183542
  • Providers like you icon
  • Horiba #1300054415
Serum Chemistry Control Kit ABX Pentra™ P MultiControl Multiple Analytes 10 X 5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1162588
  • Providers like you icon
  • PTS Diagnostics #737
Control Set A1CNow+ Controls™ Hemoglobin A1c (HbA1c) Level 1, 2
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #953771
  • Providers like you icon
  • Bio-Rad Laboratories #27124
Assayed Control Lyphochek™ Specialty Immunoassay Level 1 6 X 2 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #802401
  • Providers like you icon
  • Ortho Clinical Diagnostics #6802349
Assayed Control Vitros® Performance Verifier II Direct Total Iron Binding Capacity (TIBC) 6 X 3 mL, 6 X 5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1055478
  • Providers like you icon
  • Microbiologics Inc #8193
Molecular Diagnostic Control Panel CT / GC / TV Verification and Control Panel
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #953773
  • Providers like you icon
  • Bio-Rad Laboratories #27126
Assayed Control Lyphochek® Specialty Immunoassay Level 3 6 X 2 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #953772
  • Providers like you icon
  • Bio-Rad Laboratories #27125
Assayed Control Lyphochek® Specialty Immunoassay Level 2 6 X 2 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1165758
  • Ortho Clinical Diagnostics #6905560
Sepsis Control Set Vitros® B.R.A.H.M.S Procalcitonin (PCT) Tri-Level 3 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #802400
  • Providers like you icon
  • Ortho Clinical Diagnostics #6802348
Assayed Control Kit Vitros® Performance Verifier Direct Total Iron Binding Capacity (TIBC) 6 X 3 mL, 6 X 5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1183541
  • Providers like you icon
  • Horiba #1300054414
Serum Chemistry Control Kit ABX Pentra™ N MultiControl Multiple Analytes 10 X 5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1038826
  • Kamiya Biomedical Company #K55C-4M
Assayed Control Set K-ASSAY® Anti-Streptolysin O (ASO) / Rheumatoid Factor (RF) / C-Reactive Protein (CRP) Level 1, 2 2 X 2 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1180547
  • Ortho Clinical Diagnostics #6199943
Immunoassay Control Set Vitros® SARS-CoV-2 Antigen 2 Levels 3 X 3 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1252204
  • Siemens #11204754
Cardiac Marker Master Curve Material Atellica® IM N-Terminal Pro-Brain Natriuretic Peptide (NT-proBNP ) II Level 1, 2, 3 3 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #695669
  • Bio-Rad Laboratories #430
Assayed Control Set Lypochek® Immunology Plus Level 1, 2 12 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1240580
  • Horiba #5300100711
General Chemistry Control Set K-ASSAY® Beta-2 Microglobulin / Ferritin Level 1, 2 4 X 3 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1124024
  • Siemens #10997842
Cardiac Marker Master Curve Material Atellica® IM High-Sensitivity Troponin I Level 1, 2, 3, 4, 5 5 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #802396
  • Providers like you icon
  • Ortho Clinical Diagnostics #6801750
Assayed Control Vitros® Performance Verifier Hemoglobin A1c (HbA1c)
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #802397
  • Providers like you icon
  • Ortho Clinical Diagnostics #6801751
Assayed Control Vitros® Performance Verifier II Hemoglobin A1c (HbA1c)
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1056821
  • Kamiya Biomedical Company #K29C-4M
Diabetes Management Test Control Set K-ASSAY® Hemoglobin A1c (HbA1c) Level 1, 2 2 X 0.5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #521306
  • Providers like you icon
  • Bio-Rad Laboratories #C-315-5
Assayed Control Lyphochek® Multiple Analytes Level 2 12 X 5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1033426
  • Siemens #10311624
Tumor Marker Assay Master Curve Material ADVIA Centaur® Carcinoembryonic Antigen Level 1, 2, 3, 4, 5, 6 6 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1045920
  • Siemens #10492623
Master Curve Material ADVIA Centaur® Testosterone II Level 1, 2, 3, 4, 5, 6, 7 7 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1033383
  • Siemens #10310442
Tumor Marker Master Curve Material ADVIA Centaur® CA 125 II Level 1, 2, 3, 4, 5, 6, 7, 8 8 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1033363
  • Siemens #10310324
Anemia Master Curve Material ADVIA Centaur® Folate Level 1, 2, 3, 4, 5, 6 6 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1033564
  • Siemens #10330854
Cancer Master Curve Material ADVIA Centaur® CA 15-3 Level 1, 2, 3, 4, 5, 6, 7 7 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1108967
  • Siemens #10995724
Control Set Atellica® IM 25-hydroxyvitamin D (Vitamin D) Total 2 Levels 6 X 2 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1198811
  • Diazyme Laboratories #DZ179A-CON
Coagulation Control Set D-Dimer Level 1, 2 2 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1108894
  • Siemens #10995626
Control Set Atellica® IM Intact Parathyroid Hormone (iPTH) Level 1, 2, 3 3 X 2 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1128630
  • Siemens #10995636
Master Curve Material Atellica® IM Luteinizing Hormone Level 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 10 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1076401
  • Siemens #10698597
Master Curve Material ADVIA Centaur® Intact Parathyroid Hormone (iPTH) Level 1, 2, 3, 4, 5 5 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1136080
  • Kamiya Biomedical Company #K73C-4M
Assayed Control Set K-ASSAY® Insulin Level 1, 2 2 X 0.5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1033427
  • Siemens #10311625
Tumor Marker Assay Master Curve Material ADVIA Centaur® Alpha-fetoprotein Level 1, 2, 3, 4, 5, 6, 7 7 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1033354
  • Siemens #10310294
Cancer Master Curve Material ADVIA Centaur® Prostate-specific Antigen (PsA) Level 1, 2, 3, 4, 5, 6, 7, 8, 9 9 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #937823
  • Siemens #10699746
Nutritional Assessment / Immunoassay Master Curve Material ADVIA Centaur® 25-hydroxyvitamin D (Vitamin D) Level 1, 2, 3, 4, 5 1 X 5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1000721
  • Providers like you icon
  • Kova International #87331
Urine Chemistry Control KOVA-Trol® III Normal Level with hCG 4 X 15 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #721480
  • Horiba #1220001621
Control Set ABX Pentra™ Immuno I Low Level / High Level 2 X 3 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #879706
  • Providers like you icon
  • Ortho Clinical Diagnostics #6802411
Assayed Control Vitros® Performance Verifier Antistreptolysin O (ASO) / Rheumatoid Factor (RF)
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1224822
  • Carolina Liquid Chemistries #DZ122A-CON
Electrolyte Control Set Diazyme Carbon Dioxide (CO2) Level 1, 2 2 X 2 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1224821
  • Carolina Liquid Chemistries #DZ248A-CON
Cardiac Marker Control Set Diazyme Lipids Level 1, 2, 3 3 X 3 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #914088
  • Siemens #10385584
Veterinary Use Only Control Set K9TCM Canine Multiple Analytes Bi-Level 2 X 2 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #994071
  • Randox Laboratories Ltd USA #CF1501
Multi-Analyte Control Cerebrospinal Fluid (CSF) Level 3 10 X 3 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #914741
  • Bio-Rad Laboratories #453
Assayed Control Lyphochek® Multiple Analytes Level 3 12 X 5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1235670
  • Randox Laboratories Ltd USA #IA3111
Multi-Analyte Control Acusera™ Premium Plus Immunoassay Level 3 12 X 5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1053632
  • Randox Laboratories Ltd USA #LE5015
Control sLDL Level 3 3 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1235669
  • Randox Laboratories Ltd USA #IA3110
Multi-Analyte Control Acusera™ Premium Plus Immunoassay Level 2 12 X 5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #994069
  • Randox Laboratories Ltd USA #BE454
General Chemistry Control Bilirubin 10 X 3 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1049656
  • Siemens #10311623
Therapeutic Drug Monitoring Master Curve Material ADVIA Centaur® Digitoxin Level 1, 2, 3, 4, 5, 6 6 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1033478
  • Siemens #10317626
Cardiac Marker Master Curve Material ADVIA Centaur® TnI-Ultra® Cardiac Troponin I Level 1, 2, 3, 4, 5 5 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1045929
  • Siemens #10997193
Reproductive Hormone Assay Master Curve Material ADVIA Centaur® Sex Hormone Binding Globulin (SHBG) Level 1, 2, 3, 4, 5 5 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #994068
  • Randox Laboratories Ltd USA #AU2353
Assayed Control Urine Chemistry Level 3 12 X 10 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #994096
  • Randox Laboratories Ltd USA #IAS3115
Immunoassay Control Multiple Analytes Level 3 5 X 2 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #994088
  • Randox Laboratories Ltd USA #HE5068
Multi-Analyte Control Chemistry Premium Level 3 12 X 5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #994090
  • Randox Laboratories Ltd USA #IA2633
Immunoassay Control Set Multiple Analytes Tri-Level 4 X 3 X 5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #914968
  • Sekisui Diagnostics #K55C-4M
Antibody Test Control Set Antistreptolysin O (ASO) Level 1, 2 2 X 2 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #893997
  • Bio-Rad Laboratories #480
Assayed Control Lyphochek® Fertility Level 3 12 X 5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #901904
  • Bio-Rad Laboratories #323X
Unassayed Control Set Lyphochek® MiniPak 80 Analytes Level 1, 2 2 X 10 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #994085
  • Randox Laboratories Ltd USA #HD1667
Assayed Control Multiple Analytes Level 1 20 X 5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1100677
  • Ortho Clinical Diagnostics #2802
Immunosuppressant Drugs / Transplantation Control More Dx Rapamycin / Tacrolimus / Cyclosporine (Rap/Tac/CsA) Level 2 4 X 4 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1224832
  • Carolina Liquid Chemistries #DZ558A-CON
Sepsis Control Set Diazyme Procalcitonin Level 1, 2 2 X 3 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #960089
  • Randox Laboratories Ltd USA #LE2663
Cardiac / Lipids / General Chemistry Control Lipid Level 3 5 X 3 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #721481
  • Horiba #1220001622
Control Set ABX Pentra™ Immuno II Low Level / High Level 2 X 3 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1033423
  • Siemens #10311619
Thyroid / Metabolic Assay Master Curve Material ADVIA Centaur® Thyroxine (T4) Level 1, 2, 3, 4, 5, 6 6 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1116751
  • Bio-Rad Laboratories #528X
Assayed Control Set Lyphochek® Whole Blood Metals Tri-Level 3 X 2 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1132627
  • Siemens #10995617
Immunochemistry / Specific Protein Test Master Curve Material Atellica® IM Total IgE Level 1, 2, 3, 4, 5, 6, 7 7 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1215384
  • Fisher Scientific #NC1303426
Toxicology Control Utak PM Plus Opiates High Level 5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1234632
  • Microbiologics Inc #HE0037N
Molecular Control Kit Helix Elite™ Inactivated Standard Herpes Simplex Virus 2 5 Pellets
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1240458
  • Horiba #5390015523
Nutritional Assessment Control Set Pointe™ Ferritin Level 1, 2 2 X 3 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1209845
  • Microbiologics Inc #HE0041N
Molecular Diagnostic Control Kit Helix Elite™ Inactivated Standard Neisseria Gonorrhoeae 5 Pellets
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #762168
  • Siemens #10445988
Coagulation Control Berichrom® Heparin Heparin, Low Molecular Weight (LMW) Level 2 6 Vials
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1209848
  • Microbiologics Inc #HE0042N
Molecular Diagnostic Control Kit Helix Elite™ Inactivated Standard Trichomonas Vaginalis 5 Pellets
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1133838
  • Beckman Coulter #1667001
Control Set Sentinel Diagnostics Antigen Converting Enzyme Level 1, 2 2 X 3 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1052560
  • Diazyme Laboratories #DZ188A-CON
Metabolic Control Set Adiponectin 2 Levels 2 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1084060
  • Audit Microcontrols #K061M-6
Control Set Glycohemoglobin A1c 2 Levels 6 X 0.5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #994093
  • Randox Laboratories Ltd USA #IA2640
Immunoassay Control Multiple Analytes Premium Level 3 12 X 5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #994074
  • Randox Laboratories Ltd USA #CG5023
Multi-Analyte Control Coagulation Level 3 12 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1044398
  • Bio-Rad Laboratories #278
Assayed Control Lyphochek® Whole Blood Immunosuppressant Level 5 6 X 2 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1116669
  • Bio-Rad Laboratories #405
Assayed Control Liquichek™ Urine Metals Level 2 10 X 25 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1112950
  • Siemens #10995687
Thyroid / Metabolic Assay Master Curve Material Atellica® IM Total Thyroxine (T4) Level 1, 2, 3, 4, 5, 6 6 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1210335
  • Microbiologics Inc #8254
Molecular Control Panel Helix Elite™ Blood Culture Identification (BCID) Panel Positive Level 1, Positive Level 2, Negative Level 3 X 6 Pellets
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #994072
  • Randox Laboratories Ltd USA #CG5021
Multi-Analyte Control Coagulation Level 1 12 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1128633
  • Siemens #10995609
Master Curve Material Atellica® IM Homocysteine Level 1, 2, 3, 4, 5, 6 6 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1132630
  • Siemens #10998265
Master Curve Material Atellica® IM Procalcitonin Level 1, 2, 3, 4, 5 5 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1034277
  • Siemens #10996931
Thyroid / Metabolic Assay Master Curve Material ADVIA Centaur® Triiodothyronine (T3) Level 1, 2, 3, 4, 5, 6, 7 7 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1112956
  • Siemens #10995590
Thyroid / Metabolic Assay Master Curve Material Atellica® IM Free Thyroxine (FT4) Level 1, 2, 3, 4, 5, 6, 7 7 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #811860
  • Bio-Rad Laboratories #500X
Assayed Control Lyphochek® Anaemia 1 X 3 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1132628
  • Siemens #10995681
Thyroid / Metabolic Assay Master Curve Material Atellica® IM Total Triiodothyronine (T3) Level 1, 2, 3, 4, 5, 6, 7 7 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1124443
  • Siemens #10995664
Tumor Marker Assay Master Curve Material Atellica® IM Prostate-specific Antigen (PsA) Level 1, 2, 3, 4, 5, 6, 7, 8, 9 9 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1116665
  • Bio-Rad Laboratories #400
Assayed Control Liquichek™ Urine Metals Level 1 10 X 25 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1132623
  • Siemens #10995484
Cancer Master Curve Material Atellica® IM CA 125 2 Level 1, 2, 3, 4, 5, 6, 7 8 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1184494
  • Siemens #10995083
Immunoassay Control Set ADVIA Centaur® IL-6 Level 1, 2, 3 3 X 7 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1155731
  • Horiba #5390012529
Assayed Control General Chemistry Analytes Level 1 10 X 5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1001053
  • Fisher Scientific #22-749-701
Urine Chemistry Control KOVA-Trol® I High Abnormal Level with Urobilinogen High / Abnormal Level 8 X 60 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1129485
  • Siemens #10995492
Tumor Marker Assay Master Curve Material Atellica® IM CA 19-9 Level 1, 2, 3, 4, 5, 6, 7, 8 8 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1116680
  • Bio-Rad Laboratories #527
Assayed Control Lyphochek® Whole Blood Metals Level 1 6 X 2 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1053630
  • Randox Laboratories Ltd USA #LE5013
Control sLDL Level 1 3 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1112955
  • Siemens #10995575
Master Curve Material Atellica® IM Folate Level 1, 2, 3, 4, 5, 6 6 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1134453
  • Ortho Clinical Diagnostics #DZ179ACON
Coagulation Control Set Diazyme D-Dimer Levl 1, 2 2 X 1 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1116675
  • Bio-Rad Laboratories #482
Assayed Control Lyphochek® Fertility Level 2 12 X 5 mL
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #320373
  • Ortho Clinical Diagnostics #8748220
Clinical Chemistry Control Vitros® Isoenzyme Performance Verifier II Level 2 6 Vials Verifier, 6 X 5 mL Diluent
  Log In to Order  View Alternatives
Compare
    ,for, Item ID-
  • #1045351
  • Bio-Rad Laboratories #274
Assayed Control Lyphochek® Whole Blood Immunosuppressant Level 1 6 X 2 mL
  Log In to Order  View Alternatives
Compare Products (0) Clear Compare