Mohd Farid Laporan Latihan Industri Sarjana Muda Sains Bioperubatan UKM Tahun 3 Sesi 2007/2008-Hospital Selayang Part VIIII-Chemical Pathology Unit

Chemical Pathology Unit

Biochem is the busiest section in whole pathology lab.

OLYMPUS AU 400, OLYMPUS AU600, OLYMPUS 2700 Chemistry Immuno Analyzer

Introduction

The AU400, AU600 and AU2700 is ideal as a primary chemistry-immuno analyzer for small to medium size hospitals and laboratories or as a dedicated specialty analyzer for larger institution. Automate and consolidate chemistry-immuno testing with 122 test menu including chemistry, specific protein, urine chemistry, esoteric chemistries and tests for therapeutic drug monitoring, drug of abuse, and thyroid function. Both analyzers give random access throughput of up to 400 photometric tests per hour (up to 800 with electrolytes), on-board menu of over40 tests and user-definable sample handling option.

OLYMPUS AU400, AU600 and AU2700 is a fully automated chemistry analyzer measure component of sample (serum, plasma, urine, body fluid). First, sample is dispensed, and then the reagent is added to the sample. After mixing, absorbance is measured then calculated optical density according to absorbance measured. This machine is capable analyzing electrolytes, (Na, K, and Cl) by means of ion selective electrode.

Test Run On OLYMPUS AU 600 And AU 2700

Test

Albumin (ALB)

Alkaline Phosphatase (ALP)

Alanine transaminase (ALT)

Total bilirubin (TBIL)

Direct bilirubin (DBIL)

Total Protein-Serum (TP)

Amylase (AMY)

Aspartate transaminase (AST)

Creatine kinase (CK)

Lactate dehydrogenase (LDH)

Glucose (GLU)

Serum/ cerebrospinal fluid (CSF)

Creatine

Urea

Uric acid (UA)

Ca

Inorganic phosphate (IP)

Mg

Cholinesterase (CHE)

C-Reactive protein (CRP)

CSF Total Protein(CSF TP)

Na/K/Cl

a. Urea test

Is a qualitative in vitro determination of urea in serum, plasma/ urine on photometric system. Urea is the nitrogen containing end product of protein catabolism

This test use enzymatic UV test method

Principle of the test is

b. Uric Acid

Is a qualitative in vitro determination of uric acid in serum, plasma/ urine on photometric system. Uric acid and its salt is end product of the purine metabolism. In gout, the most common complication of hyperurcemia, increased serum level of uric acid lead to formation of monosodium urate crystals around the joints. Further cases of elevated blood concentration of uric acid are renal diseases with decreased excretion of waste products, starvation, drug abuse and increased alcohol consume as well as use of certain medicaments. High uric acid level also constitutes an indirect risk factor for coronary heart disease. Hyperuricemia is seldom observed and associated with rare hereditary metabolic disorder.

Principle of the test is uric acid is oxidized to allantoin by uricase. The generated hydrogen peroxidase reacts with 4-aminoantipyrine and N-ethyl-N (hydroxyl-3-sulfopropyl)-M-toluidin (TOOS) to a blue violet dye. Ascorbate oxidase avoids interference by ascorbic acid and other reducing substances

c. Alanine Transaminase (ALAT) With Or Without pyridoxal-5-phosphate.

This test is a qualitative in vitro determination of alanine transaminase in serum, plasma/ urine on photometric system. It uses the optimized UV test method according to IFCC (International Federation of Clinical Chemistry and Laboratory Medicine).

Principle

Addition of pyridoxal-5-phosphate (P-5-P) stabilized the transaminases and avoids falsely low values in samples containing insufficient endogenous P-5-P eg. From patient with myocardial infarction, liver disease and intensive care patient.

d. α-amylase test

α-amylase test is a qualitative in vitro determination of α-amylase in serum, plasma/ urine on photometric system. It uses the enzymatic photometric test method in which the substrate 4,6-ethynidine(G7)-p-nitrophenyl(G1)- α-D maltohepatoside (EPS-G7) is cleaved by α-amylases into various fragments. These are further hydrolyzed in a second step by α-glucosidase producing glucose and p-nitrophenol. The increase in absorbance represent the total (pancreatic and salivary) amylase activity in the sample.

                                    

e. Albumin

Purpose: Is a qualitative in vitro determination of urea in serum, plasma/ urine on photometric system.

Principle: A coloured complex is found when Bromocresol green react with albumin. The absorbance of this complex is proportional to the albumin concentration in the sample.

Normal Range

• Serum/plasma (convensional)                                    3.8 - 5.1 g/dl
• Serum.plasma (based on CRM 470 calibration)        3.5 - 5.2 g/dl

f. Aspartate Aminotransferase (ASAT)

This test is a qualitative in vitro determination of alanine transaminase in serum, plasma/ urine on photometric system. It uses the optimized UV test method according to IFCC (International Federation of Clinical Chemistry and Laboratory Medicine.)

Normal Range

g. Creatinine

Creatinine test is a qualitative in vitro determination of creatinine in serum, plasma @ urine on photometric system. It uses the enzymatic test method.

Normal Range

Serum/Plasma

Women           0.51-0.95 mg/dl

Men                 0.67-1.17mg/dl

Morning Urine

Women            29-226 mg/dl

Men                 40-278 mg/dl

h. Glucose

Principle: Glucose is phosphorylated in the presence of hexokinase and ATP. The glucose-6-phosphate produced reacts with NAD+ in the presence of glucose-6-phosphate dehydrogenase to form gluconate-6-phosphate and NADH. The increase in absorbance is proportional to the glucose concentration

Normal Range

Serum  (75 – 115 mg/dl @ 4.2-6.4µmol/l)

Urine   (there should not be any glucose in urine)

i. BIlirubin

Principle: Total bilirubin is determined in the presence of caffeine by the reaction with diazotized sulfanilic acid. Direct (conjugate) bilirubin is determined in the absence of caffeine

Normal Value

Total bilirubin (up to 17µmol/l @ up to 1 mg/dl)

Direct bilirubin( up to 4.3 µmol/l  @  up to 0.25 mg/dl)

j. LDH

i. Osmolality By OSMOMAT 030

Measurement of osmolality in plasma or serum is mostly for detection of unmeasured substances whereas in urine it is for assessment of concentrating ability of the kidney. This test is done in OSMOMAT analyzer.

Principle

The Sample solution is cooled using a Peltier element cooling system. At the same time the temperature of the sample is monitored electronically. When the sample reaches the defined temperature below the freezing point of pure water the crystallization of the solution is automatically initiated.

A stainless steel is held well below 0^oC such as water vapour in the air condensing on its tip freezes as tiny crystals; the needle tip, covered in ice crystals, is stabbed into the super-cooled solution. Thus, initiation of crystallization occurs by inoculation of the solution with ice crystals. Immediately after this the temperature of the solution begins to rise spontaneously as heat of crystallization is released during the freezing process. The rise in temperature is measured with accuracy of 1.858x10E-3^oC

Normal Range

1.0 – 3.0 mOsmol/kg

Differential Diagnosis

In renal tubular deficiency, value is below normal range whereas in diabetes insipidus the ratio is between 0.2 – 0.7 mOsmol/kg

In polyuria neurologic origin, the ratio may be normal without fluid restriction and increase after restriction

ii. AVL Compact 3 Blood Gas Analyzer

Purpose

Analysis of blood pH, pCO₂ and pO₂

Introduction

There are two broad components to the blood gas panel; respiratory and metabolic.The values reported are as follows

• pH-This is a logarithmic expression of hydrogen ion concentration;the acidity or alkalinity of the blood. The normal human arterial pH is 7.4. Any pH below this pH is acid and ph above is alkaline. There is a narrow range of pH values (7.35 to7.45) that human body and its complicated system of enzyme supported system operates within. pH value below 7.0 and above 7.6 are incompatible with life.
• HCO₃-This value is derived through the blood gas analyzer’s manipulation of the Henderson-Hasslebach equation. An uncompensated decrease in the HCO₃ value causes a decline in pH. An increase HCO₃ results in alkalinization of the blood. Either condition can be life threatening. Decrease HCO₃ is often the result of kidney or other major organ failure or uncontrolled diabetes. Increased HCO3 is more rare and is usually the result of inappropriate administration of certain drugs such as some kinds of diuretics or an excess NaHCO_3.
• pCO₂- this value is measured directly by the CO₂ electrode. An increased pCO₂ is often the result of acute, chronic or impending respiratory failure, whereas a decreased pCO₂ is the result of hyperventilation stimulated by a metabolic acidosis or hysteria and severe anxiety reactions. The normal arterial pCO₂ is 40mmHg.
• pO2-The partial pressure of oxygen in the blood is measured directly by a polarographic O2 electrode. The normal acceptable range is roughly between 85 and 100. an increased pO2 is usually the result of excessive oxygen administration that needs to be adjusted downwards on such results. A decreased pO2 is often the result of any number of respiratory or cardiopulmonary problems.

iii. Blood Gas Analyzer

On attaching the sample syringe to the cuvette, they automatically draw the sample into a heated sampling chamber with miniaturized electrodes that quickly and accurately (if properly calibrated) measure pH, pCO2 and pO2 values. Based on these three measured values, these units automatically calculate HCO3, total CO2, percent oxygen saturation and O2 content, which is based on entry of patient’s measured hemoglobin values.

           

A companion to such units, known as co-oximeter, directly measures percent oxygen saturation and hemoglobin, then accurately calculates oxygen content and carboxyhemoglobin, a value that reflects the degree of carbon monoxide in the blood in smoke inhalation victims.

           

In addition to arterial sampling, critical care specialist often order blood gas panels in blood drawn through a central venous line since pO2 and O2 content values of this blood, when compared against arterial pO2 and O2 content, enable an estimate of cardiac output, another valuable service performed by blood gas testing. Such samples are often collected and run from patients undergoing cardiac catheterization and the results must be returned while the patient is still on the table.

iv. HbA1c analysis using BIO-RAD D-10

Introduction

The BIO-RAd D-10 Hemoglobin testing system is a single module for hemoglobin analysis which cinsist of a fully automated analyzer. Hence it is intended for invitro estimation of human HbA1c in samples from normal and diabetic patient.

Principle

The D-10 uses cation exchange high pressure liquid chromatography. The sample are automatically diluted on the D-10 and injected into the analytical catridge to separate human hemoglobin subtypes and variants from hemolysed whole blood.

A programmed buffer gradient of increasing ionic strength delivers the sample to the analytical catridge where the hemoglobins are separated based upon their ionic interactions with the catridge material. The separation of HbA1c is performed rapidly and precisely with an analysis time of three minutes per sample. The separated hemoglobins then pass through the flow cell of the filter photometer where the changes in the absorbance at 415nm are measured. The D-10 software program performs the analysis of data obtained from each analysis. A sample report and chromatogram are generated for each sample and report is printed at the build-in printer.

v. ACS: 180 SE Automated Chemiluminescence System

Machine Description

The ACS:180TM SE System provide fast, accurate and reliable answers with a throughput of 180 tests per hour, a result in 15 minutes and subsequent results in 20 seconds. Result integrity is optimized by a clot detection and management system, positive sample identification and the automatic dilution features, so providing security in every result.

In chemical pathology lab, test done on ACS: 180SE Automated Chemiluminescent System are:

• T3
• T4
• Prolactin
• Etc

MODEL         

ACS 180 Se

SAMPLE REQUIRED

Serum/plasma/urine

TECHNIQUE

CLIA (direct)

CLIA COMPLEXITY 

Moderate

TEST CAPABILITIES

Antibiotics

Gentamicin, tobramycin, vancomycin

Chemistries

CK-MB, myoglobin, troponin I, homocysteine; (BNP) 2

Antiarrhythmics       

Digoxin (no pretreatment), digitoxin (no pretreatment)

Anticonvulsants       

Carbamazepine, phenobarbitol, phenytoin, valproic acid

Antiasthmatics         

Theophylline

Endocrine Function

hCG (with onboard autodilute), LH, FSH, prolactin, estradiol, progesterone, testosterone

Diabetes        

C-peptide, insulin Under development.

Antianemics

Ferritin, B12, folate, RBC folate

Thyroid markers      

T4, T3, FT3, FT4, TSH, 3rd-gen TSH, antiTP/-GPO, T-up

Immunoglobulins     

IgE

Proteins        

Ferritin

Tumor markers        

CEA, PSA, AFP, BR (27-29), OV (RUO) CA 19-9 (RUO), cPSA

Other (ROTORS)     

Intact PTH, cortisol (serum, urine), DPD, insulin, c-peptide

vi. Advia Centaur Machine

vii. AxSYM

The AxSYM system is a random and continuous access immunoassay analyzer capable of processing tests using proven technologies. The AxSYM system uses fluorescence polarization immunoassay (FPIA), microparticle enzyme immunoassay (MEIA) and Radiative Energy Attenuation (REA) technologies. These principles have been discussed at the virology section in microbiology laboratory.

viii. Viva E DADE BEHRING/Siemens Viva ProE System