Tests at central laboratory E – H

Alternative test name

ECT

Purpose and scope

Ecarin clotting time was developed for monitoring the action of anti-thrombin agents. Ecarin is an enzyme in snake venom (from Echris carinatus) that converts prothrombin to meizothrombin, which promotes clot formation. In clinical trials of new anticoagulant medicines, ECT serves as a marker of the effect on blood coagulation, because it activates prothrombin in the absence of any co-factors.

Method

Absorbance

Sample requirements

109 mmol/L buffered sodium citrate plasma with a 9:1 ratio of blood to citrate.  For long-term storage, keep samples at –40°C or lower for a maximum of 2 months.

Maximum turnaround time

24 h

Purpose and scope

Excessive alcohol consumption damages the liver, heart and brain. Alcohol interferes with many drugs, so all trials in healthy volunteers exclude subjects who abuse alcohol. Most trial protocols also require that subjects refrain from alcohol for at least 24 h before admission to a trial. The laboratory measures urine alcohol as an indicator of ethanol consumption within 8 h before sample collection.

Method

Enzymatic reaction rate

Sample requirements

Urine

Maximum turnaround time

24 h

Purpose and scope

Factor X is a vitamin K-dependent, plasma glycoprotein, which is synthesized in the liver. During coagulation, Factor X is proteolytically activated to the serine protease Factor Xa, either by the intrinsic pathway (factor IXa, factor VIIIa, cellular surface, and calcium ions), or the extrinsic pathway (factor VIIa, tissue factor, cellular surface, and calcium ions). Factor Xa combines with calcium, factor Va, and the negatively-charged phospholipid surface, to form the prothrombinase complex that is responsible for the rapid conversion of prothrombin to thrombin. Primary congenital deficiency of Factor X is a rare inherited disorder. Secondary (acquired) factor X deficiency is due to other diseases, such as systemic amyloidosis, liver disease, hyperfibrinolysis, and disseminated vascular coagulation (DIC). Patients on oral anticoagulant therapy, or with vitamin K deficiency, have reduced plasma concentrations of Factor X.

Method

Factor X activity in a patient’s plasma is determined by doing a modified prothrombin time (PT) test. Patient plasma is diluted, and added to plasma deficient in Factor X. Correction of the clotting time of the deficient plasma is proportional to the concentration or % activity of Factor X in the patient plasma.

Sample requirements

109 mmol/L buffered sodium citrate plasma with a 9:1 ratio of blood to citrate.  Add the sample exactly to the line marked on the tube; under- or overfilled-tubes may give erroneous results. Centrifuge and test within 2 h of collection. For long-term storage, keep samples at –40°C or lower for a maximum of 2 months. Thaw frozen specimens to 37°C for at least 15 min; after thawing, do the assay within 2 h.

Maximum turnaround time

24 h

Alternative test name

FOB

Purpose and scope

In healthy subjects, there is no detectable bleeding from the gastrointestinal tract (GIT). However, diseases of the GIT can cause bleeding (eg ulcerative colitis, duodenal ulcer, and infection with organisms such as Campylobacter jejuni). Also, some drugs can cause bleeding in the GIT. Sometimes, patients notice blood in their stools, but, often, the amount of blood is so small that patients are unaware of it. That is known as occult bleeding.
Medicines that affect the coagulation pathways or platelet activity can increase the risk of bleeding. Therefore, in studies of such medicines, it is important to ensure that potential subjects do not have any pre-existing bleeding from the GIT. Testing stool samples for faecal occult blood (FOB) lets us exclude subjects who might be at risk of excessive GIT bleeding after treatment with the study drug.

Method

Oxidation of guaiac by hydrogen peroxide

Sample requirements

Collect 3 stool samples, on 3 different days, using a fresh test card for each sample.
Use a small stool sample, prepared by the subject, according to the instructions in each pouch. Test cards should be developed no sooner than 48 h after sample application. Test cards bearing samples may be stored at room temperature for up to 14 days before developing.

Maximum turnaround time

24 h

Purpose and scope

Ferritin is a sensitive indicator of body iron stores, and correlates well with stainable bone-marrow iron. Serum ferritin concentrations of <10 µg/L almost always indicate iron-deficiency anaemia. Conversely, in anaemia of chronic disorders, ferritin concentrations are increased. Concentrations are also increased in other anaemias, including aplastic anaemia, sideroblastic anaemia, and chronic haemolytic anaemias. In idiopathic haemochromatosis and in multiply-transfused patients, serum ferritin concentrations may be extremely high.
In the screening of subjects for clinical trials of new medicines, ferritin is measured to differentiate iron-deficiency anaemia from anaemia of chronic disorders.

Method

Enzymatic reaction rate

Sample requirements

Serum. Ferritin is stable in serum for 7 days at 2–8°C, or for up to 6 months at –20°C.

Maximum turnaround time

24 h

Purpose and scope

After vascular injury and the initiation of the coagulation cascade, fibrinogen is converted into fibrin, which forms, with platelets, the fibrin plug. Fibrinogen levels are reduced after blood coagulation; in clinical trials of new medicines, that reduction serves as a marker of drug effect on coagulation. Underlying disease, eg liver disease and disseminated intravascular coagulation, can also reduce fibrinogen.

Method

Absorbance

Sample requirements

109 mmol/L buffered sodium citrate plasma with a 9:1 ratio of blood to citrate. Store at –40°C for up to 2 months.

Maximum turnaround time

24 h

Alternative test name

FDP

Purpose and scope

Naturally-occurring FDP were found first in pathological sera. Subsequently, a haemagglutination-inhibition immunoassay test was developed that was sensitive enough to detect FDP in 95% of healthy people. In clinical trials of new medicines, FDP serve as a marker of effects on blood coagulation.

Method

Immunoassay

Sample requirement

2 mL blood in the tubes provided with the kit. Those tubes contain enzyme inhibitors. Mix immediately, by inverting several times; leave the tubes at room temperature, to allow the blood to clot. Centrifuge and collect the serum. The sample may then be stored in the fridge for up to a week, or at –15?C to –20?C for a longer period.

Maximum turnaround time

24 h

Alternative test name

FSH

Purpose and scope

Follicle stimulating hormone (FSH) is secreted by the β-cells of the anterior pituitary, under the control of gonadotropin releasing hormone (GnRH), which is produced by the hypothalamus. FSH facilitates the development and maintenance of gonadal tissues, which synthesize and secrete steroid hormones (oestradiol, progesterone and testosterone). Circulating concentrations of FSH are controlled by those steroidal hormones, by a negative feedback mechanism.
Normal sexual function in both men and women depends on the concentrations of FSH and luteinising hormone (LH), although the secretory patterns are very different for the 2 sexes. In mature women, FSH initiates the growth and development of ovarian follicles. During ovulation, when the follicle is ruptured, the now-called corpus luteum secretes oestradiol and progesterone, which control the circulating concentrations of FSH by negative feedback. In menopause, a diminished ovarian function results in reduced secretion of oestradiol, and the lack of negative feedback leads to increased circulation of FSH concentrations.
In mature men, FSH is associated with the stimulation and maintenance of spermatogenesis. Testosterone and oestradiol provide negative feedback to the hypothalamus, thus controlling the release of FSH. Infertility in men may be due to hypogonadism resulting from primary testicular failure, which causes a dramatic rise of circulating FSH concentrations.
In clinical trials of new medicines, FSH is not measured routinely. FSH may be measured when the study medicine is expected to affect blood concentrations of FSH. Also, FSH, LH and oestradiol are measured to confirm that a woman is post-menopausal.

Method

Two-step immunoenzymatic ‘sandwich’ assay

Sample requirements

For analysis, use serum or plasma (heparin). Samples are stable for 8 h at room temperature, 48 h at 2–10°C, or 3 months at –20°C.

Maximum turnaround time

24 h

Alternative test name

NEFA, free fatty acids

Purpose and scope

Non-esterified fatty acids are fatty acids that are not esterified with cholesterol or glycerol. NEFA circulate in plasma in ionised form; the flux of NEFA through plasma is very sensitive to the level of blood glucose. Insulin resistance in type II diabetes may be mediated by the excessive release from adipocytes of NEFA, which serve as energy substrates for muscle, thereby stimulating gluconeogenesis. Plasma NEFA concentration is a useful indicator of glucose/lipid homeostasis in studies of drugs for the treatment of type II diabetes.

Method

Colorimetric

Sample requirements

Serum or plasma (EDTA, sodium fluoride, sodium citrate or ammonium oxalate). Assay samples promptly, within 3 h. If necessary, store samples at –20°C for up to 24 h. Gently invert thawed samples several times before testing. At sample reception, make an aliquot of the sample and freeze it. Use this as a backup sample if the assay fails.

Maximum turnaround time

24 h

Purpose and scope

Protein S is a vitamin K-dependent non-enzymatic plasma protein that is synthesised in the liver. About 40% of protein S in the plasma is in the free (unbound) form. Free protein S acts as a cofactor to activated protein C, which degrades clotting factors Va and VIIIa, thereby regulating blood coagulation. Protein S deficiency may be hereditary or acquired, and is associated with a high risk of venous thromboembolism, especially in young people. In clinical trials of new medicines, free protein S serves as a marker of effects on blood coagulation.

Method

Turbidimetric

Sample requirements

109 mmol/L buffered sodium citrate plasma with a 9:1 ratio of blood to citrate. Add the sample exactly to the line marked on the tube; under- or overfilled-tubes may give erroneous results. Centrifuge and test within 2 h of collection. For long-term storage, keep samples at –40°C or lower for a maximum of 2 months. Thaw frozen specimens to 37°C for at least 15 min; after thawing, do the assay within 2 h.

Maximum turnaround time

24 h

Alternative test name

FBC, CBC

Purpose and scope

FBC comprises red blood cells (RBC), white blood cells (WBC) and platelets (PLTS). As the method of measuring the constituent cells is the same.
Red blood cells
Haemoglobin (HB). This is a specialized protein responsible for carrying oxygen in the red blood cells. It is reduced in patients with anaemia, for which there are many causes, including: deficiencies of iron (including menstruating women), folate and vitamin B12; genetic disease, eg thalassaemia and sickle cell disease; anaemia of chronic disease; acute blood loss; haemolytic anaemia; bone marrow failure; metabolic. In clinical trials of new medicines, the measurement of haemoglobin is important to ensure that subjects are not anaemic before the trial, as most trials involve collection of significant amounts of blood. It can also provide a clue as to whether a subject might have recently participated in a trial. Drugs cause anaemia as a result of haemolysis and bone marrow failure. A raised haemoglobin is less common, and is not often encountered in clinical pharmacology. If found, it would usually represent underlying disease which would need investigating.
Mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC) are measures of haemoglobin in the red cells, and closely reflect the total haemoglobin concentration.
RBC is a measure of the number of red cells, and is usually reduced in anaemia in parallel with haemoglobin, but can sometimes still be normal. A raised RBC, which can be absolute or relative (reduced plasma volume), usually indicates disease, but can be the result of dehydration.
The packed cell volume (PCV), or haematocrit (HCT), is the percentage volume of blood taken up by red cells. It is usually reduced in anaemia in parallel with the haemoglobin, but can sometimes be normal. A raised PCV usually indicates disease, but can be the result of dehydration.
Mean cell volume (MCV) is the volume of a red cell. In anaemia, it may be reduced (microcytic, hypochromic, eg iron deficiency), normal (normocytic, normochromic, eg haemolytic anaemia), or increased (macrocytic, eg vitamin B12 and folate deficiency). MCV may also be normal if there is dual pathology, eg iron deficiency and folate deficiency. In that case, a blood film may clarify the situation. Non-haematological disease can also cause an increase in the MCV, eg alcohol and hypothyroidism.

White blood cells

WBC comprise 2 groups and 5 subtypes of cells, as follows.
Phagocytes: neutrophils, eosinophils, basophils and monocytes
Lymphocytes
WBC are involved in the body’s defences against infection, and act in synergy linked by 2 complementary protein systems: the immunoglobulins and complement. WBC also have a role in allergic responses. There are many causes of raised WBC, including infection, disease (eg inflammatory disease), drugs (eg steroids), cancer (eg leukaemia) and growth factors (eg G-CSF), allergic disease, and increased de margination of white cells. Causes of reduced WBC include disease (eg Felty’s), drugs (eg carbimazole), and infection (eg influenza). Drugs cause leucopenia (low WBC) by bone marrow suppression, stimulating the production of antibodies against WBC, or by increasing margination of WBC. In clinical trials of new medicines, WBC is measured for safety purposes. A decrease or increase in WBC might represent drug-induced leucopenia or leucocytosis respectively. In trials of medicines such as G CSF, a change in WBC might indicate a pharmacodynamic effect.

Platelets

Platelets are involved in control of bleeding after injury to a blood vessel. Causes of a low platelet count include disease (eg idiopathic thrombocytopenic purpura), bone marrow failure, and drugs. Drugs can cause a low platelet count by bone marrow suppression, immune mechanisms, or platelet aggregation. Sometimes, platelet counts can be erroneously low, owing to aggregation during collection and transport. Raised platelet counts are less common, and can be caused by bleeding and essential thrombocythaemia. In clinical trials of new medicines, platelets are measured for safety reasons. A low platelet count might represent drug-induced thrombocytopenia

Method

Cytochemistry, impedance, absorbance and flow cytometry

Sample requirements

EDTA whole blood

Maximum turnaround time

24 h

Alternative test name

GGT

Purpose and scope

Gamma-glutamyl transferase (GGT) is present in serum, and in all cells except those in muscle. Serum GGT originates primarily from liver, and is increased in all forms of liver disease, including alcohol abuse. It is highest in patients with biliary obstruction and more sensitive than AST and ALT in the detection of obstructive jaundice, cholangitis and cholecystitis. Only moderate increases occur in patients with infectious hepatitis; AST and ALT are more sensitive indicators of infectious hepatitis than is GGT.
In clinical trials of new medicines, GGT mainly serves as a test of liver function. An increase in GGT and other liver function tests, such as serum bilirubin, alanine aminotransferase (ALT), and aspartate aminotransferase (AST), might represent drug-induced liver dysfunction. GGT is usually regarded as abnormal only if raised by at least 1.5 or 2 times the upper limit of normal. Results should be interpreted with caution because of the known increases in ALT, AST, and GGT in healthy subjects who are resident, and have been given placebo (Rosenzweig et al 1999; Narjes and Nehmiz, 2000; Mertz et al 1997). One possible cause of those increases is an imbalance between reduced physical activity and calorie intake. The composition of the diet may also play a role. Excess calories and a high carbohydrate intake (Porikos and Van Itallie, 1983; Purkins et al 1997) cause increased enzyme levels.

Method

Enzymatic rate method according to Szasz

Sample requirements

Serum or heparinised plasma. Centrifuge the samples within two hours of collection. It is stable for 7 days at room temperature or 7 days at 2–8ºC. The sample can be frozen at –20°C for up to 2 months. Once thawed, do not refreeze.

Maximum turnaround time

24 h

Purpose and scope

Gastrin is produced and stored in endocrine G cells of the antral mucosa of the stomach. It is secreted in response to antral distension; partially digested protein products; amino acids; and by vagal stimulation resulting from smelling, tasting, chewing or swallowing food. Also, caffeine, alcohol, hypoglycemia, antacids and elevated calcium levels stimulate gastrin release. Gastrin is the most potent known stimulator of gastric acid secretion.
Gastrin exists in 3 molecular forms in the blood and tissues: big gastrin (G-34), little gastrin (G-17) and mini-gastrin (G-14). There are 2 types of G-34 and G-17: non-sulphated (I) and sulphated (II). Both G-34 and G-17 contribute to the stimulation of gastric acid secretion, but they have different clearance rates. In humans, G-17 has a circulating half-life of about 9 min, while G-34 has a half-life of about 35 min. G-34 is the major circulating gastrin in fasting serum, but G-17 concentrations increase 2- to
3-fold after feeding, until both forms are present in similar amounts.
Fasting gastrin concentrations in a healthy person are typically <100 pg/mL. Abnormal gastrin values occur for various reasons, including Zollinger-Ellison tumours, pernicious anaemia, peptic ulcer disease, and in patients taking proton pump inhibitors (PPI). Gastrin assays can therefore play an important role in the diagnosis of disease, and also in clinical trials to study the effects of drugs on circulating gastrin.

Method

Enzyme-labelled immunometric assay

Sample requirements

Serum, samples are stable for 4 h at 2–8°C, and for 30 days at –20°C.

Maximum turnaround time

24 h

Alternative test name

GAF

Purpose and scope

CCR1 and CCR3 are chemokine receptors expressed on allergic effector cells (mast cells, eosinophils, and basophils). Inhibition of CCR1 and CCR3 might benefit patients with asthma or rhinitis.
Depending on the cell type, CCR1 and CCR3 regulate cell generation, recruitment, activation and survival. CCR1 and CCR3 functional receptor occupancy can be determined by measuring shape changes in monocytes and eosinophils, respectively.
In clinical trials of new medicines, CCR1 and CCR3 functional receptor occupancy are used as a pharmacodynamic measure of monocyte and eosinophil activation.

Method

Cytofluorometric method

Sample requirements

3.8% tri-sodium citrate whole blood: the ratio of blood to citrate must be 9:1. Do not test clotted samples; obtain a repeat specimen, if necessary.
Include up to 2 blood samples in a batch; leave a gap of 2 h between batches.
Process samples within 30 min after collection; after that time, the eosinophils and monocytes start to change shape spontaneously.

Maximum turnaround time

24 h

Alternative test name

Obestatin preprohormone, GHRL, MTLRP

Purpose and scope

Ghrelin is a hunger hormone, produced by P/D1 cells lining the fundus of the human stomach and by epsilon cells in the pancreas. It stimulates appetite. Ghrelin concentrations increase before a meal, and decrease shortly afterwards.
In clinical trials, ghrelin can be used as a marker of obesity.

Sample requirements

Collect blood into a 5 mL EDTA aprotinin tube. Keep the sample on ice at all times. Centrifuge the sample immediately at 1600 G for 15 min at 4°C. Acidify the blood by spiking it with 1N HCL to give a final concentration of 0.05 N (50 µL 1N HCL for every 1 mL plasma). Freeze sample at –70°C.

Maximum turnaround time

Batched

Purpose and scope

Glucagon is a 29-amino-acid peptide hormone, synthesised as proglucagon in the alpha cells of the pancreatic islets. It stimulates glucose synthesis when blood glucose concentrations fall, and so has an important role in maintaining blood glucose levels.
In a clinical trial we might measure glucagon: to ensure that potential subjects are eligible for a trial; as a pharmacodynamic marker; or as a pharmacokinetic variable.

Method

Competitive enzyme-linked immunoassay (EIA)

Sample requirements

EDTA tube containing aprotinin. Assay plasma as soon as possible after separation. If there will be a delay, aliquot samples and freeze them at or below –30°C.

Maximum turnaround time

Batched

Purpose and scope

Blood glucose is raised in people with either type 1 or type 2 diabetes mellitus. Rarely, blood glucose falls due to organic disease, or drugs. Glucosuria (the presence of glucose in urine) occurs when the concentration of glucose in the blood exceeds the renal threshold. In clinical trials of new medicines, glucose in serum and urine is used mainly as a screening test to exclude diabetes mellitus. In studies of hypoglycaemic agents, glucose serves as a pharmacodynamic marker. Urine glucose is used to monitor the effects of drugs such as steroids and diazoxides.

Method

Timed endpoint method

Sample requirements

Serum or heparinised plasma. Centrifuge the samples within two hours of collection. It is stable for 24 h at room temperature or 7 days at 2–8ºC. The sample can be frozen at –20°C for up to a year. Once thawed, do not refreeze.
Urine assays should be performed within 2 hours of collection. For timed specimens, keep the collection container in the refrigerator or on ice during the time period.

Maximum turnaround time

24 h

Alternative test name

GH, GrH, hGH, somatotropin

Purpose and scope

Human growth hormone is a polypeptide hormone secreted by the anterior pituitary gland. It promotes protein conservation and synthesis, increases glucose transport, and facilitates the build up of glycogen stores.
Blood growth hormone concentrations vary considerably throughout the day, making it difficult to define a reference range, or to judge an individual’s status from a single measurement. Many factors, including periods of sleep and wakefulness, exercise, stress, hypoglycaemia, oestrogens, and corticosteroids can affect the secretion of growth hormone.
Measurement of hGH aids the diagnosis and treatment of various forms of inappropriate growth hormone secretion, eg dwarfism, resulting from hyposecretion, and acromegaly, resulting from hypersecretion. In clinical trials of new medicines that affect the brain, growth hormone may serve as a pharmacodynamic marker.

Method

One-step immunoenzymatic sandwich assay

Sample requirements

Serum or plasma, samples are stable for 8 h at room temperature and 48 h at 2–8°C. Store samples at –20°C for longer storage.

Maximum turnaround time

24 h

Purpose and scope

Haptoglobin is a liver-synthesised protein, consisting of 4 peptide chains, linked into 2 pairs by disulphide bonds. Haptoglobin serves in the preservation of iron, and in the prevention of damage to renal tubules. It also plays a significant role in acute inflammatory processes. Low haptoglobin concentration may be caused by genetic deficiency, hepatocellular disease, or increased breakdown of red blood cells. In clinical trials, haptoglobin is monitored as an indicator of drug-induced haemolysis.

Method

Turbidimetric

Sample requirements

Serum, samples are stable up to 7 days at 2–8?C, and up to 2 days at 15–25?C

Maximum turnaround time

24 h

Alternative test name

H Pylori

Purpose and scope

Helicobacter pylori is a gram-negative, non-spore-forming bacterium, with a characteristic helical morphology. The organism resides mainly within, or beneath, the mucous gel layer adjacent to the epithelial cells of the stomach. The presence of H pylori in the human stomach is strongly associated with peptic ulcer, and its detection allows the prescription of eradication therapy. Antimicrobial therapy is usually combined with a proton pump inhibitor to reduce acid output, and accelerate ulcer healing.
Immunoassay is the most common indirect detection method, owing to the ease of testing. In clinical trials, evidence of infection with H pylori is most commonly an exclusion criterion.

Method

Immunoassay

Sample requirements

Serum or plasma

Maximum turnaround time

24 h

Alternative test name

HEP LMW

Purpose and scope

Heparin is the drug of choice in short-term anticoagulant therapy. Heparin is a sulphated glycosaminoglycan with the ability to accelerate (up to 2000-fold) the inhibitory effect of antithrombin on thrombin, factor Xa, and other coagulation proteases. In recent years, low molecular weight heparin (LMWH) has been favoured over unfractionated heparin (UFH) because of its longer half-life. LMWH appears to catalyse the reaction between factor Xa and antithrombin more readily than the reaction between thrombin and antithrombin. That means that the factor Xa inhibition test is the most useful test for assaying the widest variety of therapeutic heparin preparations

Method

Sample requirements

109 mmol/L buffered sodium citrate plasma with a 9:1 ratio of blood to citrate. Add the sample exactly to the line marked on the tube; under- or overfilled-tubes may give erroneous results. Centrifuge and test within 2 h of collection. For long-term storage, keep samples at –40°C for a maximum of 2 months. Thaw frozen specimens to 37°C for at least 15 min; after thawing, do the assay within 2 h.

Maximum turnaround time

24 h

Alternative test name

Hep B core antibody, HbcAb

Purpose and scope

Hepatitis B is a highly infectious disease that is transmitted through body fluids eg blood. Hepatitis B infection can be fatal or lead to chronic liver disease. HBcAb is used to detect past or present infection with hepatitis B. Staff who handle blood are at risk of hepatitis B infection; therefore we screen potential subjects to ensure that they are not infected. We also measure HBcAb levels to monitor the response of our staff to hepatitis B immunisation.

Method

Qualitative immunoassay

Sample requirements

Serum, heparinised plasma, citrated plasma or EDTA plasma. Samples are stable for 8 h at room temperature and for 48 h at 2–10°C.

Maximum turnaround time

24 h

Alternative test name

Hep B surface antigen, HbsAg

Purpose and scope

Hepatitis B is a highly infectious disease that is transmitted through bodily fluids eg blood. Hepatitis B can be fatal or lead to chronic liver disease. As our studies involve multiple blood samples, all our study subjects are screened to ensure they do not carry hepatitis B infection, so that the risk to staff and other study subjects from blood-borne diseases is minimised. HbsAg indicates acute or chronic infection. It is therefore measured to assess infectivity. In addition, some of our staff have pre-vaccination samples that indicate past exposure to hepatitis B (positive HBcAb). We measure their HbsAg (together with e antigen), to ensure that they are not an infection risk.

Method

One step enzyme immunoassay

Sample requirements

Serum, heparinised plasma, citrated plasma or EDTA plasma. Samples are stable for 8 h at room temperature and for 48h at 2–10°C.

Maximum turnaround time

24 h

Alternative test name

Hep C virus antibody, HCVab

Purpose and scope

Hepatitis C is a highly infectious disease that is transmitted through bodily fluids, eg blood. Hepatitis C infection can be fatal or lead to chronic liver disease. HCVAb is used to detect past or present infection with hepatitis C. Staff who handle blood are at risk of hepatitis C infection; therefore, we screen potential subjects to ensure that they are not infected.

Method

Indirect immunoenzymatic assay

Sample requirements

Serum, heparinised plasma, citrated plasma or EDTA plasma. Samples are stable for 8 h at room temperature and for 48h at 2–10°C.

Maximum turnaround time

24 h

Alternative test name

HIV I & II antibodies

Purpose and scope

HIV 1 & 2 are viruses that cause autoimmune deficiency disease (AIDS), and are transmitted through bodily fluids, eg blood. HIV I & 2 antibodies are used to detect infection with HIV1 & 2. Staff who handle blood are at risk of HIV 1 & 2 infection; therefore we screen potential study subjects to find out if they are infected.

Method

One-step immunoenzymatic method

Sample requirements

Serum, heparinised plasma, citrated plasma or EDTA plasma. Samples are stable for 8 h at room temperature and for 48 h at 2–10°C.

Maximum turnaround time

24 h