Archive for the ‘Laboratory Procedures’ Category

Glucose Determination -Ortho-toluidine Manual Method

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Posted 17 Sep 2011 — by admin
Category Clinical Chemistry, Laboratory Procedures

Precautions  for Glucose Determination (Ortho-Toluidine Method)

As presented by  kit procedure

1. Patient should have fasted for 8-12 hours.
2. Unhemoylzed, non icteric and non turbid serum should be used to avoid interferences
with the procedure.
3. The reagent contains sodium azide, which is corrosive, so PPE should be worn.
4. The solution should be brought to a boil to ensure proper reaction.

MANUAL PROCEDURE PROPER: ORTHOTOLUIDINE  METHOD

1. Prepare Three tubes labeled, SA (Sample)/ C (Control), ST (Standard) and RB (Reagent Blank).

2. To the SA/C tube add 0.1 ml of the test specimen/ Control specimen.

3. To the ST tube add 0.1 ml of the standard stock solution.

4. To the RB tube add 0.1 ml of distilled water.

5. Add 4 ml of glucose reagent to all tubes. Cap and mix by gentle inversion.

6. Boil all tubes at 100 degrees centigrade for 8 minutes.

7. Cool tubes in running tap water for about 2 minutes.

8. Read absorbance of solutions in the spectrophotometer with appropriate cuvets at 636 nanometers against the RB (Reagent Blank).

9. Compute for the Cu (Concentration of the Unknown making use of the formula:

Cu= Absorbance of Unknown(Au) multiplied by the Concentration of the
Standard(Cs) divided by the Absorbance of the Standard (As)

Adapt the unit of the Cs

Normal Values = 60 – 100 mg/dL
to convert values to mmol/L multiply values in mg/dL with 0.0555

Normal high can reach   as far  as  120 mg/dL

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Urinalysis: The Diagnostic Procedure

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Posted 16 Mar 2011 — by admin
Category Health Procedures, Keeping Healthy, Laboratory Procedures

Urinalysis is one of the most common diagnostic procedures or tests requested by doctors. This is probably because of the easy availability of specimen, ease of collection and relatively inexpensive cost of the test. However, the simplicity of the procedure should not be a reason for either the patient or medical technologist to be too lax about urinalysis. Although the test seems easy to do, it is one of the most useful diagnostic tools used by doctors to screen diseases. Here are some of the important things you must know about the test.

Illnesses Detected

Urinalysis detects various medical conditions. Since urine is an ultra filtrate of blood, it contains information about your body’s most important processes. The few amount of urine can help you diagnose possible kidney related problems such as urinary tract infection, renal stones and glomerulonephritis. It can also detect chronic conditions like diabetes mellitus. Usually, doctors request for urinalysis when you show symptoms like low back pain, painful urination, abdominal pain and blood in the urine. The diagnostic procedure is very useful in diagnosing urinary tract infections, UTI.

Patient Preparation

The patient preparation depends on the kind of urine specimen requested from you. However, the most common specimen required is the random and first morning specimen. Since random specimen may be taken anytime of the day, there are no special preparations needed. For the first morning specimen, you have to collect the urine upon waking up in the morning. This is more preferred as the various urinary constituents have been pooled overnight which represent a better view of the body’s metabolism. For both types, you need to do a “clean-catch mid-stream”. For ladies, wash the vaginal area prior to collection. Allow the few drops of urine to come out before collecting the middle part. Avoid contaminating the specimen with tissue paper or water.

Test

The actual urinalysis test will only take 10-15 minutes. During this time, the medical technologist will do a visual, chemical and microscopic examination. After the test, your doctor will then interpret the results with consideration of your medical history, signs and symptoms and results from other diagnostic procedures.

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Alternate Sites for Capillary Puncture

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Posted 13 Mar 2011 — by admin
Category Health Procedures, Laboratory Procedures

There are several alternate sites for capillary puncture. These alternate sites are also good alternatives when the designated puncture area is injured.

Capillary puncture is the collection of blood through the capillaries; hence, through the capillaries of the skin. The most common sites are the pads of the fingers.

Alternate sites include:

Ear lobes

Big toes

Heel of infants

These are alternate sites of puncture that you can take advantage of. Remember to wipe the first drop of blood before collection as this is contaminated with tissue juices. Knowing the correct procedure in collecting from these alternate sites will ensure the reliability of your laboratory results.

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Capillary Puncture: Important Things You Must Know

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Posted 08 Mar 2011 — by admin
Category Hematology, Laboratory Procedures

Capillary Puncture
Image Credit: aeonbox.com

There are different ways to draw blood from a patient and capillary puncture is one of them.  If you compare it with venipuncture and arterial puncture, it is the easiest way to obtain a blood specimen. Usually doctors request the procedure when there is minimal volume of blood needed. If you have a blood request stating capillary puncture in the laboratory request form, here are some basic information about the procedure.

Capillaries

Also known as the “finger stick”, the capillary puncture involves the smallest blood vessels in the body. Since the capillaries are found all throughout the body and in a more superficial location, it only involves poking the skin with a sharp object called a lancet.  The most common sites for specimen collection are the palmar surfaces of the fingers, ear lobe and big toe or heel for the infants. Once the blood starts to ooze from the punctured site, the medical worker will collect the specimen in a capillary tube or in an appropriate specimen container.

Preparation

There are no special patient preparations indicated for capillary puncture. In fact, it only requires minimal training to correctly perform the blood collection. Even non- health workers can obtain the blood provided that they have the necessary equipment and basic knowledge on the proper collection technique. Oftentimes, diabetic patients are the most common lay persons who perform the capillary puncture at home for their daily blood sugar monitoring.

Procedure

The principle in obtaining blood through capillary puncture is the same with venipuncture and arterial puncture. Of course, the health worker needs to correctly identify the patient and choose the most appropriate site. Highly calloused fingers or those with skin injuries like hematoma and bruises and edematous areas are not recommended. Once the health provider has settled with the site, he/she has to clean the site of puncture with a cotton and alcohol starting from the center moving outwards. Using a swift and deliberate motion, he/she will then puncture the skin with a lancet, wipe the first drop of blood and collect the blood using a capillary tube.

Precautions

During the collection, squeezing of the punctured must be avoided. It leads to dilution of blood with tissue juices, thereby leading to erroneous results. Since young children are the common patients indicated for capillary puncture, assistance from adults and use of restraining devices may be necessary. If your kids are the patients, you must help the health worker explain the procedure to your child. Be truthful about what to expect. Tell them about the minimal but tolerable pain that they will feel. Do not tell them it does not hurt, because it does. Reassure them though that the pain is tolerable.

Aftercare

Since capillary puncture involves a minor puncture, there are no known health risks for it, if performed by knowledgeable personnel. However, you must apply pressure to the site for 3 to 5 minutes to stop the bleeding. The whole procedure only takes up to 5 minutes to complete. After the capillary puncture, you can always go back to your regular activities.

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Things you Must Know about Pap Smear

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Posted 12 Dec 2010 — by admin
Category Histopathology, Laboratory Procedures

By Engracia S. Arceo, MPH, RMT

Papanicolaou test or also known as pap smear is a screening test for cervical cancer. The procedure gathers the cells in the cervix and uses them to detect abnormalities. It is an effective way to check for early changes in the integrity of cells. Because it is cheap and simple, it is widely available in most health care facilities in different countries.

Who Should be tested?

The test is highly recommended to all women belonging to the age group 21 to 65. If you had vaginal intercourse earlier, you do not have to wait to reach 21 years old. It is done on a regular basis especially during the reproductive year. Some organizations recommends that it should be done every 5 years or more often depending on the results of the previous test.

Are there Special Preparations?

To increase the accuracy of the test, most doctors recommend that you have your pap smear after your menstruation. Two days before the test, you should avoid douching or vaginal intercourse. If you are using vaginal creams, you should also notify your doctor.

How Long is the Procedure?

The specimen collection will only take 3 to 5 minutes. The doctor will use a speculum to widen the opening of the vagina. The procedure may cause a slight discomfort. After the collection, the smear will be sent to the laboratory for processing.

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Cervical Cancer- Protect Yourself

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Posted 11 Dec 2010 — by admin
Category Diseases and Conditions, Histopathology, Laboratory Procedures

By Engracia S. Arceo, MPH, RMT

Cervix refers to the lower part of the uterus. When problems in the cervix arise, the symptoms are so general that they go unnoticed. If you are a woman aged 18 years old and above and is sexually active, it is imperative that you undergo pap’s smear to see whether you have the deadly disease. Here are some facts about cervical cancer.

Symptoms

Some patients who have cervical cancer do not present any sign of the illness. However, in most women, the common symptoms can include abnormal vaginal bleeding, unusual heavy discharge, and pelvic pain, pain during urination and pain and bleeding during a sexual intercourse. In rare cases, infections are also present.

Diagnosis

The use of symptoms alone cannot diagnose cervical cancer. For the preliminary assessment, your doctor may request a pap’s smear to check for the integrity of the individual cells. Usually, cancerous cells present themselves well under the microscope. If you get a positive Pap’s smear test, further testing is required.

Treatment

Women positively diagnosed with cervical cancer have many options for treatment. Surgery, radiation therapy, chemotherapy or a combination of all of these may be warranted. If you have questions about the treatment, you should always ask your doctor about it.

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In Vitro Fertilization – The Way to Overcome Infertility

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Posted 05 Dec 2010 — by admin
Category Alternative Medicine, Laboratory Procedures, Physiology, artificial methods

By:  Engracia S. Arceo, MPH, RMT

In these modern times, in vitro fertilization is one way to overcome infertility. Infertility produces mental and emotional depression. Because the ultimate goal of couples is to have a child, inability to have may lead to your breakup. But with the advances in medicine, it is now possible to defy nature and conceive a child even with the so called “artificial method”.

Preparation

Prior to the In-Vitro Fertilization (IVF), the couple has to undergo a thorough physical and medical assessment. The doctor checks the sperm quality of the male and tracks the menstrual cycle of the female. When everything is clear, the procedure commences.

Procedure

IVF starts when the egg cell from the sperm and egg cell are allowed to meet outside the woman’s body. When fertilization is successful, the fertilized egg will be injected back to the female uterus for normal intra-uterine development to occur. From this time onwards, the female will experience the normal course of pregnancy and childbirth.

Success

One IVF may not necessarily lead to successful pregnancy. Some couples experience several failed procedure before they finally have their baby. Some common scenarios include miscarriage and premature birth. While many couples only aim for a single baby, you have the option to ask your IVF provider to implant multiple embryos.

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The Differences of Serum and Plasma

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Posted 27 Nov 2010 — by admin
Category Clinical Chemistry, Laboratory Procedures

You can outline the differences of serum and plasma in the several  aspects. They are both blood specimens used in laboratory testing, but each has its own characteristics.

Criteria Serum Plasma
Anticoagulant none Present
Protein present albumin , globulin albumin, globulin & fibrinogen
Rimming of specimen done not done
Standing of specimen done Not done
Revolutions per minute (RPM) 2,000-3,000 2,000 – 3,000
Time of centrifugation 5 – 10 minutes 5-10 minutes
Supernatant fluid Supernatant fluid when clotted blood is centrifuged. Supernatant fluid when unclotted blood is centrifuged.

These are major differences of serum from plasma. What is important is when to know what specimen is ideal for a particular laboratory blood test.

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Precautions in Performing Bilirubin Tests

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Posted 13 Nov 2010 — by admin
Category Clinical Chemistry, Laboratory Procedures

Bilirubin is the major bile pigment in the body.  There are crucial precautions you should observe in performing bilirubin tests because the substance can be affected by many factors. Here are precautions that are observed in the Jendrassik and Grof method and Evelyn and Malloy method.

Avoid hemolysis of blood specimen.

Bilirubin is a degradation product of Red Blood Cell or RBC, so any lysis or rupture of these blood cells will increase inaccurately the results of the bilirubin test.

Avoid exposure to light.

Biluribin is photosensitive. It is easily destroyed by light, so exposing it to natural or artificial light will erroneously decrease its laboratory results.

Maintain the correct pH.

Maintaining the correct pH or alkalinity and acidity of the test solution and reagent will ensure the reliability of results. This is vital precaution in performing bilirubin tests.

Avoid interference from proteins and foreign substances.

Protein and foreign substances will greatly affect you bilirubin tests.  Be sure to cover your solutions at all times with a rubber stopper or a parafilm. This will ensure that the results of your bilirubin tests are accurate and precise.

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ROUTINE URINALYSIS

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Posted 30 Sep 2010 — by admin
Category Clinical Microscopy, Laboratory Procedures

By: Lou Grace T. Manalili, RMT, DVM

Two general standpoints may be considered in the routine urinalysis. First is for the management and diagnosis of renal or urinary tract disease and second, the detection of systemic or metabolic diseases indirectly to the kidney.

Routine urinalysis is composed of four parts:

  • SPECIMEN EVALUATION – this implies specimen acceptability. Proper specimen labeling, proper use of preservative and any transportation delays in getting the specimen to the laboratory are some considerations to consider.
  • PHYSICAL TESTS – these include color, odor, volume, osmolality and specific gravity of urine.
    • Color- urochrome is a pigment responsible for the normal color of urine that varies from pale yellow to amber and this is also due to small amounts of pigments uroerythrin and urobilins. Any abnormalities in color maybe a cause of a renal disease or just a physiologic cause from food intake or medicine.
    • Odor – faint aromatic scent is normal, a change in odor like foul or ammoniacal indicates bacterial contamination.
    • Volume – adult daily average volume of urine ranges from 1.2 Liters to 1.5 Liters.
    • Osmolality –500 to 850 mOsm/kg of urine will be produced by an individual in a regular diet taking 8 to 10 glasses of water a day.
    • Specific gravity – this varies from 1.016 to 1.022 during a 24-hour period.
  • CHEMICAL EVALUATIONS
    • pH in urine – this is an indication of the capability of the kidney to sustain normal hydrogen ion concentration in plasma and extracellular fluid.
    • Protein – occurrence of this in urine may arise after a tough exercise or dehydration or patients with urinary tract infection, hemorrhage or with fever.
    • Glucose – in a typical urine sample, glucose is absent but this maybe present in the urine if blood glucose level exceeds 180 to 200 mg/dl.
  • SEDIMENT EXAMINATION – this is done through the use of a microscope and usually for the detection of diseases of the kidney. Presence of casts, increase amount of pus cells, blood cells or bacteria indicate urinary tract infection and/or a renal disease.

Routine urinalysis also has two major components: the macroscopic and the microscopic testing. Available reagent strips are being used for the macroscopic examination that includes the chemical and physical tests of urine.

  • Steps for Macroscopic Routine Urinalysis
  1. Examine and evaluate urine specimen. Properly label, indicate name, age, gender of owner and record time received, volume and color.
  2. Pour 10-15ml of urine in a centrifuge tube and take note on the report if the volume is less than the required volume.
  3. Determine transparency or clarity as to clear, slightly turbid or turbid.
  4. Determine specific gravity, pH, glucose and protein with the use of reagent strips. Compare strips to color chart and record results.
  5. Prepare urine specimen for microscopic test.
  • Steps for Microscopic Routine Urinalysis
  1. Centrifuge urine sample of 10-15ml in a tube for about 5 minutes.
  2. After centrifugation, carefully tilt the tube bottoms up to separate sediments from the supernatant. Save the supernatant for possible retesting.
  3. Gently suspend the sediment on a glass slide and place a cover slip on top of it.
  4. Examine under low power objective in at least 10 low power fields sediments with low refractive index like, epithelial cells, mucus threads, urates, casts, crystals and bacteria. Report as few, moderate or many.
  5. Red blood cells and pus cells are identified and counted under a high power objective in at least 10 high power fields. Report as cell/hpf.
  6. Comment and take note for presence of large amount of crystals, bacteria, yeast or any microorganism. Perform confirmatory test if needed.

Review results, make a report on the test then affix your signature on the form to determine examiner.

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