LDH

Question 1

Summary

Answer 1

Lactate dehydrogenase (LDH) is an enzyme, consisting of five
different isoenzymes, which catalyze the interconversion of
L-lactate and pyruvate. LDH is present in the cytoplasm of all human
tissues with higher concentrations in liver, heart and skeletal muscle
and lower values in erythrocytes, pancreas, kidney and stomach.
Increased LDH activities are found in a variety of pathological
conditions such as myocardial infarction, cancer, diseases of liver,
blood or muscle. However, because of the lack of organ specificity,
determination of its isoenzymes or other enzymes such as alkaline
phosphatase or ALAT/ASAT is necessary for differential diagnosis.

Question 2

Method

Answer 2

Optimized UV-test according to IFCC (International Federation of
Clinical Chemistry and Laboratory Medicine)

Question 3

R1

Answer 3

N-Methyl-D-Glucamine
L-Lactate

Question 4

R2

Answer 4

NAD+

Question 5

Warnings and Precautions

Answer 5

1. Reagent 1 contains sodium azide (0.95 g/L) as preservative. Do not swallow!
2. In very rare cases, samples of patients with gammopathy might give falsified results
3. Please refer to the safety data sheets and take the necessary
   precautions for the use of laboratory reagents.

Question 6

Wavelength

Answer 6

340/410 nm (bichromatic)

Question 7

Measurement

Answer 7

Linear kinetics

Question 8

Interfering substance

Answer 8

Ascorbic acid
Bilirubin (conjugated)
Bilirubin (unconjugated)
Lipemia
Sulfapyridine
Sulfasalazine
Hemoglobin

Question 9

Conversion factor

Answer 9

0.0167

Question 10

Reference Range

Answer 10

Female: < 247 U/L
< 4.12 µkat/L

Male: < 248 U/L
< 4.14 µkat/L