Specimen quality

Question 1

Peripheral Blood Lymphocytes and PUBs

Answer 1

Should not be clotted and should be collected in a vacutainer containing sodium heparin

Question 2

BMs

Answer 2

• Should not be clotted and should be collected in a syringe containing sodium heparin
• Cell density should be determined before culturing to ensure proper dilution in culture media. (Coulter counter or hemocytometers can be used.)
• One to four million cells per ml is an acceptable cell density for bone marrow cultures.

Question 3

solid tissues

Answer 3

• Skin biopsy punch should contain dermal layers where dividing cells are located.
• A minimum of 1mm3 is required to establish a flask culture.
• Solid tumors samples should be part of the specimen submitted for pathology. In other words as free as possible of normal and fatty tissue and necrotic areas.

Question 4

amniotic fluid

Answer 4

• Should be straw colored in appearance. Yellow colored samples may be contaminated with urine. The yellow color indicates a low acidity. The Fern test (streak of specimen is allowed to air dry on a slide to observe crystalline patterns) will indicate urine if the specimen dries in a cube shape pattern (typical of uric acid), but will indicate amniotic fluid if the specimen dries in a fern shaped pattern.
• Bloody specimens require a check for resistance to denaturation by alkali as determined by the alkaline denaturation assay. This assay can determine whether the blood is of fetal or maternal origin. The results can assist in confirming or ruling out maternal cell contamination in a sample, which has chromosomal mosaicism. blood alkaline denaturation assay

Question 5

CVS

Answer 5

From 5 - 25mg of intact villi is obtained with this procedure. Adherent maternal decidua should be removed to prevent maternal cell contamination prior to culturing. (Forceps and the dissecting microscope are useful to get rid of all maternal decidua.) The villi will be branched in appearance and lighter as compared to the decidua, which will be more sheet-like and darker.

Question 6

Troubleshooting

Answer 6

1. Notification of Appropriate Authorities (e.g. supervisor/director) Any problem in specimen quality should be noted in the specimen log and in the patient file. The supervisor should be notified immediately to assist in determining the appropriate troubleshooting measures to be followed. The director should be notified in those circumstances where more input is needed or where it appears that a repeat sample will have to be requested from the physician.
   2.Patient info
   3.Specimen info
   4.Document priority status based on reason for referral
   STAT:newborn infants in the critical care unit who are suspected of having an inherited genetic defect; amnio; BMs from patients awaiting therapy