Tissue sample:
(1) nonviable tissue
(2) tissue received in fixative
(3) tissue frozen or overheated
(4) tissue dried out
Transport of specimen:
(1) improper transport media
(2) excessive time in transit
(3) temperature during transport out of acceptable range
(4) antibiotic or other additive
(5) leakage or loss of material
Contamination:
(1) Mycoplasma
(2) bacterial contamination of specimen
Defect in culturing system (chemical toxic to cells, inadequate quality):
(1) syringe
(2) plasticware
Incubator failure:
(1) delivery of CO2: insufficient or excessive
(2) temperature under or above specified range
Media:
(1) outdated or deteriorated media
(2) defective or deficient media
(3) contamination
