LABORATORY ACTIVITY 5 Flashcards
can be routinely collected for plasma and peripheral blood mononuclear cells (from the median cubital vein) using centrifugation and a density gradient medium such a Ficoll-Hypaque.
Whole blood
Fresh blood is collected in the presence of anticoagulants such as EDTA (pH 8) or Citrate
Whole blood
Blood collected in tubes can be stored at [?] and must be processed as soon as possible to obtain maximum DNA yield and quality.
4C
Otherwise, it can be stored under [?] a several weeks, and under [?] several months
-18° C
-70°C
Use [?] to minimize contamination.
good phlebotomy technique
Considering the risk of infection (e.g. hepatitis B and HIV viruses) it is necessary to follow safety protocols (disposable gloves, surgical mask, etc.) when working with human native material
Whole Blood
Anyone performing [?] procedures should review the following recommendations to ensure that they are not placing persons in their care at risk for infection.
fingerstick
Fingerstick devices should never be used for more than one person due to risk of transmission of other [?].
bloodborne infectious diseases
Wash your hands with warm [?] and dry hands thoroughly or perform hand hygiene using an alcohol-based hand sanitizer.
soapy water
• Put on [?] for the collection of the fingerstick blood specimen.
gloves
• Hold the hand of the person being tested in a [?] position and massage the hand to improve blood flow into the fingers.
downward
• Use the middle or ring finger for the specimen collection. Locate a puncture site it should be [?] on the fleshy part of the fingertip.
slightly off-center (lateral side of)
• Clean the puncture site with a [?] and allow it to air dry.
70% isopropyl alcohol pad
• Use the manufacturer-provided collection device or a [?] that retracts upon puncture for performing the fingerstick. Follow the manufacturer’s instructions if using their collection device.
disposable, single-use lancet
• Press the fingerstick collection device or lancet firmly against side of the finger pad and activate to perform the puncture. If using a lancet, make a single puncture in [?].
one smooth motion
• Gently squeeze the [?] of the finger to form a drop of blood at the puncture site. Avoid squeezing the finger repeatedly or too tightly. Wipe away the first drop of blood and follow manufacturer instructions to fill the capillary collection tube or apply the second drop of blood to the test device.
base
• Dispose of used fingerstick collection devices and lancets immediately at the point of use in an approved sharps container. Never [?] lancets.
reuse
• Apply firm pressure to the puncture site with clean gauze for [?] after collecting the specimen to ensure bleeding has stopped. If needed, apply [?] to site.
five to ten seconds
self-adhering latex-fee adhesive strip
• Properly remove [?] and discard in appropriate receptacles. Change gloves between contacts with each person being tested. Change gloves that have touched potentially blood-contaminated objects or fingerstick wounds before touching clean surfaces.
gloves
• Wash and dry hands thoroughly or perform [?] immediately after removal of gloves and before touching medical supplies intended for use on other persons.
hand hygiene
- Gather necessary supplies
Gloves
DBS card
Lancet (2mm)
Skin disinfectant
Gauze or cotton wool
Pen
Sharps container
- Complete all necessary paper work
• Clinic registers
• Laboratory request/Report form
• DBS card
- Choose area to be pricked and warm this area by gently [?] it, you may ask the mother to this task
rubbing
- Wash and glove hands. If gloves have powder, [?] powder
wash off
Position the baby with the foot or hand down, clean the spot to be pricked with skin disinfectant, allow to dry for
30 seconds
- Gently squeeze and release the area to be pricked until it is ready to be bled, prick the infant in the selected spot with the [?].
2mm lancet
• Infants 6 weeks to 4 months -
heel
• Infants 4 months - 10 months -
big toe
• Infants >10 months or >10 Kg -
finger
- Wipe away the [?], allow a large drop of blood to collect.
first spot of blood
- Touch the filter paper gently against the large drop and allow it to completely fill the circle. Collect at least [?] full circles.
3
• The blood sample can also be applied with a [?] onto the sampling paper, thus avoiding potential sampling errors
calibrated pipette
- Clean area with gauze and apply gentle pressure to stop bleeding. Ensure the wound is clean and bleeding has stopped for at least [?]. Complete documentation and recheck the wound before the baby leaves your care.
five minutes
Drying DBS
1. Leave DBS on a drying rack in a clean, dry, protected area until dried completely, for at least [?].
2. Keep lab requests forms with [?]
4 hours or overnight
DBS cards
While drying, DBS should not be touched and should be kept out of
direct sunlight
If your site collects DBS for both [?], then two sets of drying racks are needed. Label one drying rack for EID DBS and the other for VL DBS.
Early Infant Diagnosis (EID)* and HIV viral load (VL) monitoring
• You may label each DBS card [?] at the time of specimen collection in order to ensure that it is dried in the correct rack
“EID” or “VL”
In order to avoid nucleic acid contamination, the DBS for EID and VL should NEVER be dried together on [?].
the same rack
are used for HIV diagnostic testing, while
EID DBS
are used for HIV monitoring
X VL DBS
This type of contamination can lead to
inaccurate test results
- Prior to saliva collection, ensure that the subject’s mouth is free of food or other foreign substances by having the subject rinse their mouth with water and avoiding eating or drinking for [?] before collecting the sample
30 min
- Open a [?] centrifuge tube with [?] of DNA stabilization buffer2 making sure to avoid touching the inside of the cap or tube, and have the subject spit 2.5 ml of saliva into the buffer solution.
15 ml
2.5 ml
Note: Collecting more than [?] of saliva can lead to sample degradation from an insufficient ratio of sample to DNA stabilization buffer.
2.5 ml
Collecting [?] will reduce expected yields from the protocol.
too little saliva
To evaluate collection volumes, use the [?] on the side of the tube.
numbered gradients
Replace cap and mix by inversion until the mixture is [?]. Vigorous shaking is not necessary.
homogenized
Store the samples at [?] for short-term storage or [?] for long-term storage (>3 months).
RT
4 °C
Use only [?]that have been designed for sampling the nasopharyngeal mucosa.
synthetic fiber swabs with thin plastic or wire shafts
Do not use [?], as they may contain substances that inactivate some viruses and may inhibit molecular tests.
calcium alginate swabs or swabs with wooden shafts
CDC recommends collecting only the [?], although an OP specimen is an acceptable specimen type.
NP specimen
If both NP and OP specimens are collected, combine them in a single tube to maximize [?] and limit use of testing resources.
test sensitivity
Procedure for collecting an NP specimen
- Tilt patient’s head back [?].
- Gently and slowly insert a minitip swab with a flexible shaft (wire or plastic) through the nostril parallel to the palate (?) until resistance is encountered or the distance is equivalent to that from the ear to the nostril of the patient, indicating contact with the nasopharynx.
- Gently [?] the swab.
- Leave swab in place for several seconds to [?].
- Slowly remove swab while [?] it. Specimens can be collected from both sides using the same swab, but it is not necessary to collect specimens from both sides if the minitip is saturated with fluid from the first collection.
- If a [?] create difficulty in obtaining the specimen from one nostril, use the same swab to obtain the specimen from the other nostril.
- Place swab, [?] first, into the transport tube provided.
70 degrees
not upwards
rub and roll
absorb secretions
rotating
deviated septum or blockage
tip
Procedure for collecting an OP specimen
• Insert swab into the [?].
• Rub swab over both tonsillar pillars and posterior oropharynx and avoid touching the [?].
• Place swab, [?] first, into the transport tube provided.
posterior pharynx and tonsillar areas
tongue, teeth, and gums
tip
Nasal mid-turbinate (NT) specimen (performed by a healthcare provider or the patient after reviewing and following collection instructions):
• Use a [?] swab.
• Tilt patient’s head back [?].
• While gently rotating the swab, insert swab less than one inch (about [?]) into nostril parallel to the palate (not upwards) until resistance is met at turbinates.
• Rotate the swab several times against [?] and repeat in other nostril using the same swab.
• Place swab, [?] first, into the transport tube provided.
tapered
70 degrees
2 cm
nasal wall
tip
