Test Catalog

Test ID: NSFIB    
Nonalcoholic Steatohepatitis (NASH)-FibroTest, Serum and Plasma

Method Description Describes how the test is performed and provides a method-specific reference

NASH-FibroTest Interpretation:

Proprietary algorithm owned by BioPredictive.


Alpha-2-Macroglobulin and Haptoglobin:

In this method, the light scattered onto the antigen-antibody complexes is measured. The intensity of the measured scattered light is proportional to the amount of antigen-antibody complexes in the sample under certain conditions. If the antibody volume is kept constant, the signal behaves proportionally to the antigen volume.


A reference curve is generated by a standard with a known antigen content on which the scattered light signals of the samples can be evaluated and calculated as an antigen concentration. Antigen-antibody complexes are formed when a sample containing antigen and the corresponding antiserum are put into a cuvette. A light beam is generated with a light-emitting diode, which is transmitted through the cuvette. The light is scattered onto the immuno-complexes that are present. Antigen and antibody are mixed in the initial measurement, but no complex is formed yet. An antigen-antibody complex is formed in the final measurement.


The result is calculated by subtracting value of the final measurement from the initial measurement. The distribution of intensity of the scattered light depends on the ratio of the particle size of the antigen-antibody complexes to the radiated wavelength.(Unpublished Mayo method; instruction manual: Siemens Nephelometer II, Siemens, Inc; Version 2.3. 2008; Addendum to the Instruction Manual 2.3, 08/2017)


Alanine Aminotransferase (ALT):

Alanine aminotransferase (ALT) activity is determined by a kinetic method using a coupled enzyme reaction where the rate of NADH consumption is measured at 340 nm. The NADH decrease is directly proportional to the ALT activity.(Package insert: Roche ALT reagent. Roche Diagnostics 2018)


Apolipoprotein A1:

Anti-apolipoprotein A-1 antibodies react with the antigen in the sample to form antigen/antibody complexes which, following agglutination, can be measured turbidimetrically.(Package insert: Tina-quant Apolipoprotein A-1. Roche Diagnostics;, 2019)


Gamma-Glutamyltransferase (GGT):

This is an enzyme colorimetric method (rate method) where gamma-glutamyltransferase (GGT) transfers the gamma-glutamyl group of the substrate (L-gamma-glutamyl-3-carboxy-4-nitroanilide) to glycylglycine. The amount of 5-amino-2-nitrobenzoate liberated is proportional to the GGT activity and can be determined photometrically.(Package insert: Boehringer Mannheim GGT reagent, Indianapolis, IN, 2017)


Bilirubin, Total:

Total bilirubin, in the presence of a suitable solubilizing agent, is coupled with 3,5-dichlorophenyl diazonium in a strongly acidic medium. The color intensity of the red azo dye formed is directly proportional to the total bilirubin and can be determined photometrically.(Package insert: Bilirubin Total Gen. 3. Roche Diagnostics; 2019)


Aspartate Aminotransferase (AST):

Aspartate aminotransferase (AST) is measured by a coupled enzyme kinetic method where the rate of decrease of NADH, determined at 340 nm, is directly proportional to the AST activity.(Package insert: Roche AST reagent. Roche Diagnostics; 2019)


Cholesterol, Total:

Cholesterol is measured by an automated enzymatic method. The reagents include cholesterol ester hydrolase, cholesterol oxidase, and a coupled colorimetric end-point chemistry system.(Package insert: Roche Cholesterol Reagent. Roche Diagnostics; 2018)



Serum triglycerides are measured by an automated enzymatic method. The chemistry includes hydrolysis of the triglycerides and phosphorylation of the resulting glycerol. The method is referenced to the Center of Disease Control standardized method performed in the Cardiovascular Risk Assessment Laboratory.(Package insert: Bayer Triglyceride Reagent. Bayer Diagnostics Corp;package insert: Roche Triglyceride Reagent. Roche Diagnostics; 2020)


Glucose, Fasting:

Glucose in the serum, in the presence of hexokinase, is converted to glucose-6-phosphate (G-6-P). Glucose-6-phosphate dehydrogenase (G-6-PDH) oxidizes G-6-P in the presence of NADP to gluconate-6-phosphate and NADPH. The rate of NADPH formation is directly proportional to glucose concentration in the serum and is measured photometrically.(Package insert: Roche Glucose Reagent. Roche Diagnostics;  2019)

PDF Report Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.

HAPTF, A2MF: Monday through Saturday; 3 p.m.

ALTF, GGTF, TBILF, ASTF, CHOLF, TRIGF, GLURF: Monday through Sunday; Continuously

APOAF: Monday through Saturday; Continuously

Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.

1 day

Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Clinic Laboratories until the release of the test result

3 days

Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

7 days

Performing Laboratory Location Indicates the location of the laboratory that performs the test