Activated Partial Thromboplastin Time (aPTT) Test

The aPTT is one of several blood coagulation tests. It measures how long it takes your blood to form a clot. Normally, when blood vessels are damaged, proteins in the blood are called clotting factors, and they come together in a certain order to form blood clots and quickly stop bleeding.

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What is the Activated Partial Thromboplastin Time (aPTT) test? 

 Activated Partial Thromboplastin Time (aPTT), also called partial thromboplastin time (PTT), is a screening test that helps evaluate a person’s ability to form blood clots appropriately.

This test is done to detect bleeding and clotting disorders and to monitor the treatment with blood-thinning medicines. In cases of unexplained bleeding, inappropriate blood clotting, or recurrent miscarriages, and sometimes before a scheduled surgery, an aPTT test is performed. These tests are usually performed with other tests like prothrombin time and thrombin time to analyse the clotting time accurately.

If the values were higher than normal, it could be due to a bleeding disorder or liver disease. If the values are lower than normal, they can indicate that you may have a chance of getting blood clots and several miscarriages.

What are the other names for the Activated Partial Thromboplastin Time (aPTT) test? 

Other names are aPTT and PTT test.

What parameters are included in an Activated Partial Thromboplastin Time (aPTT) Test?

There is only one parameter.


What does the Activated Partial Thromboplastin Time (aPTT) test measure? 

This test measures the time taken by the blood to form a clot after the addition of substances (reagents) that activate the clot formation.

In the event of any bleeding, the body responds by forming a blood clot as quickly as possible. This process of blood clotting or coagulation is called hemostasis, and it involves a series of chemical reactions in the blood (coagulation cascade). During this process, the blood proteins called factors are activated one after another in a series. These activate coagulation factors that lead to the formation of fibrin mesh around the platelets and other blood cells at the site of bleeding, and this complex hardens to form a “blood clot."

The coagulation cascade proceeds through two pathways: the intrinsic pathway and the extrinsic pathway. These pathways will later be merged together into a common pathway. The Activated Partial Thromboplastin Time (aPTT) test measures the function of blood coagulation factors I, II, V, XII, VIII, IX, X, and XI, along with other factors like Prekallikrein (PK), and High Molecular Weight Kininogen (HK), that form parts of the intrinsic and common coagulation pathways.

This aPTT test result is compared to a control sample of normal blood.

The aPTT test is usually performed along with a Prothrombin Time (PT) test to evaluate the cause of a coagulation defect, if any. 


What’s the normal range of Activated Partial Thromboplastin Time (aPTT) test?

21 to 35 seconds.


Who should get an Activated Partial Thromboplastin Time (aPTT) test? 

The PTT may be recommended along with other tests, such as a PT when you have:

  • Unexplained bleeding or easy bruising.

  • Blood clots in a vein or an artery.

  • This acute condition, such as disseminated intravascular coagulation (DIC), might cause both bleeding and clotting as a coagulation factor is used up at a rapid rate.

  • A chronic condition such as liver disease may affect clotting.


A PTT may be ordered.

  • as part of an evaluation for lupus anticoagulant (LA), anticardiolipin antibodies (ACA), and antiphospholipid syndrome, when you have had a blood clot or when a woman has had recurrent miscarriages.

  • When you are switched from heparin therapy to longer-term warfarin (Coumadin®) therapy, the two are overlapped and both the PTT and PT are monitored until you have stabilized.

  • When you have a surgical operation scheduled, you may have ordered a PTT prior to surgery when the surgery carries an increased risk of blood loss and/or when you have any clinical history of bleeding, such as frequent or excessive nose bleeds and easy bruising, which may indicate the presence of a bleeding disorder.

Are preparations needed for the Activated Partial Thromboplastin Time (aPTT) test?

Fasting is not required for this test.

What is the cost of a Urine Culture test?


What is the type of sample required? 

This test requires a urine sample.

Who performs a Urine Culture and Sensitivity test?

A healthcare provider, who is also called a phlebotomist, usually asks the patient/customer to collect the midstream urine, but any healthcare provider trained in collecting urine can perform this task. These samples are sent to a lab where a medical laboratory scientist prepares the samples and processes the tests on analysers or manually.

What should I expect during my Urine Culture and Sensitivity test?

A urine culture requires a clean urine sample. This term means there are a lot of microorganisms in the air. The urine sample is as free from other outside contaminants as possible, such as normal bacteria that live on your skin. You may provide this sample at the lab testing facility. In certain situations, you may be able to collect the urine sample at home.

Steps include:

  • Wash hands with soap and warm water thoroughly.

  • Wipe thoroughly to clean with antiseptic wipes the opening of the urethra (the vulva and vaginal area or the head of the penis).

  • Please let out a small amount of urine into the toilet and then stop midstream.

  • Place a sterile container under the vulva or penis before you resume peeing. Don’t let the container touch your skin.

  • Collect the designated amount of urine in the sterile container (usually 1 to 2 ounces). And most people fill the cup before they finish peeing.

  • And stop midstream again (if possible) and hold the sterile container out of the way until you’re done urinating.

  • Keep the sterile container down, place a lid on it (if provided), and put it in the designated collection area. Please don’t forget to wash your hands again.

What are other ways to collect a urine sample?

A healthcare provider may use one of these methods for infants and young children, and adults who are ill, hospitalized, or elderly. A healthcare provider can use one of these methods:

  • Catheterization: The healthcare provider inserts a catheter (a thin, flexible tube) through the urethra to reach your bladder. And the urine flows out of the catheter into a sterile container or a collection bag.

  • Aspiration: The healthcare provider inserts a thin needle through the numbed abdominal skin into your bladder to aspirate the urine into a collection bag or sterile container.

  • Urine bag (U bag): For infants and young children, you can attach a urine collection bag sticky with adhesive directly to their penis or over their vulva. After your child urinates, you can empty their urine into a lidded sterile container. Keep the sterile container refrigerated until you can drop it off at the laboratory or your healthcare provider’s office.

What should I expect after my Urine Culture and sensitivity test?

Once the healthcare provider has collected the urine sample, it will be sent to the laboratory for processing or testing. When the reports are ready, your healthcare provider will share the results with you.

What is the risk of the  Urine Culture and Sensitivity test?

Collecting a urine sample is not painful unless you are experiencing any pain while urinating because of an existing urinary tract infection (UTI). And there aren't any risks associated with preparing for or collecting urine.

When can I expect my Urine Culture and Sensitivity test results?

These reports are available via email or WhatsApp within 48 hours of the collection of the blood sample.

What do the results of a Urine Culture and Sensitivity test mean?


The results of urine culture and sensitivity are often interpreted in conjunction with the results of a complete urinalysis and with regard to how the sample was collected and whether any symptoms were present. Since some of the urine samples have the potential to be contaminated with bacteria normally found on the skin (normal flora), care must be taken with interpreting the culture results.

Positive urine culture: This is typical. The presence of a single type of bacteria growing at higher colony counts is considered a positive urine culture.

  • For clean urine samples that have been properly collected, cultures with greater than 100,000 colony forming units (CFU)/milliliter of one type of bacteria usually indicate infection.

  • And in some cases, however, there may not be a significantly high amount of bacteria even though infection is present. Sometimes, the lower numbers (1,000 up to 100,000 CFU/mL) might indicate the infection, especially if you have any symptoms present.

  • Likewise, for samples that are collected by using a technique that minimizes the contamination, such as a sample collected with a catheter, results of 1,000 to 100,000 CFU/mL can be considered significant.

The results from the urinalysis can also be used to help interpret the results of a urine culture. For example, the positive leukocyte esterase (a marker of the white blood cells) and the nitrite (a marker for bacteria) help confirm a UTI.


If a culture is positive, antibiotic susceptibility testing may be performed to guide the treatment therapy.

Although there are a variety of bacteria that can cause UTIs, most are due to Escherichia coli (E. coli), a bacteria that is common in the digestive tract and found routinely in the stool.


Usually, the other bacteria that commonly cause UTIs include

  • Proteus

  • Klebsiella

  • Enterobacter

  • Staphylococcus

  • Acinetobacter

Occasionally, a UTI may be due to a yeast such as Candida albicans.

Negative urine culture: The culture that is reported as “No growth in culture after 48 hours of incubation” usually indicates that there is no infection. If there are any symptoms that might persist, however, a urine culture test can be repeated on another sample to look for the presence of the bacteria at lower colony counts or the other microorganisms that may cause the symptoms. Usually, there is the presence of white blood cells and a low amount of microorganisms in the urine of a symptomatic person, a condition that is known as an acute urethral syndrome.

Contamination: If the culture growth shows several different types of bacteria are present, it is likely that the growth is due to the contamination. This is especially true in voiding the urine samples if the organisms that are present include Lactobacillus and/or other common nonpathogenic vaginal bacteria in women. If the symptoms persist, the healthcare practitioner can request a repeat urine culture on a sample that was more carefully collected. However, if there is one type of bacteria present in significantly higher colony counts than the others, for example, 100,000 CFUs/mL versus 1,000 CFUs/mL, then additional testing can be done to identify the predominant bacteria.


What are normal Urine Culture and Sensitivity test results?

The culture yields no growth after 48 hours of incubation.

Reference ranges may vary slightly among different laboratories. Usually, some labs use different measurements or may test different samples. Speak to your doctor about the meaning of your specific test results.


What other tests might I have along with this test?

Complete Urine Examination, Ultrasound abdomen (USG).

How do I book a Urine Culture and Sensitivity test at home?

Log on to and submit your details. Our highly trained, professional, and vaccinated eMedics will be at your doorstep within 60 minutes or at the time booked by you.

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