136 Section IV ■ Miscellaneous Sampling

section of right lobe of liver. The sample should

be cut into 5-mm cubes.

(2) Percutaneous biopsy (21)

Several needles are available (16 or 18 gauge)

(a) Aspiration or suction needles (Jamshidi,

Klatskin, and Menghini)

(b) Cutting type needles (Tru-Cut and VimSilverman)

(c) Spring loaded devices

d. Procedure

(i) Make a small (0.25- to 0.5-cm) incision in the

right anterior to midaxillary line at the 9th or

10th rib.

(ii) Flush the needle with saline.

(iii)Insert the needle parallel to the bed surface and

advance toward the opposite shoulder.

(iv) The needle is advanced 2 to 3 cm into the liver

and suction applied, pulling a segment of liver

into the needle. Spring-loaded needles do not

need suction applied.

7. Muscle

a. Collect if mitochondrial disorder or muscular dystrophy suspected (19,22). Surgeon or neurologist

may be more adept at obtaining sample.

b. Collect within 2 to 3 hours of death.

c. Procedure

(1) Make a 2- to 3-cm incision over mid quadriceps.

(2) Muscle clamps are not required but may be

used for ease of sample removal.

(3) Excise three 2- by 0.5-cm sections of muscle if

possible.

(4) Process the samples as indicated in Table 25.3.

(5) If incisional biopsy is not possible, three cores of

quadriceps muscle should be obtained using a

percutaneous biopsy needle.

 Other tissues may be sampled if specific related

diagnoses are being considered. Some metabolic

specialists have suggested collecting vitreous fluid

for organic acids and bile for acylcarnitines.

Table 25.3 Processing of Fluid and Tissue Samples Obtained by Perimortem Sampling

Tissue Type Testing Sample Collection and Handling Storage

Blood Inborn errors of metabolism Newborn screen paper Room temperature

Inborn errors of metabolism Dried spots on filter paper Room temperature

No plastic bag

DNA extraction 5 mL in EDTA tube Refrigerate at 4°C

Do not freeze

Chromosome analysis

Microarray analysis

5 mL in lithium heparin tube Keep cool or at room temperature

Do not freeze.

Quantitative amino acids

Fatty acids

Carnitine

5 mL in lithium heparin tube,

separate within 20 min

Freeze and store at –70°C

Urine Organic acids

Amino acids

Orotic acid

Acylglycines

5–10 mL Freeze and store at –70°C

CSF Amino acids 1+ mL Freeze and store at –70°C

Skin Fibroblast culture

• Chromosome analysis

• Genetic mutations

• Enzyme analysis

Viral transport media Keep cool or at room temperature

Do not freeze

Liver (3 pieces) Histopathology

Enzymology

Electron microscopy

5-mm cube each sample Freeze and store at –80°C

Muscle (3 pieces) Light microscopy Wrap in moist saline soaked gauze;

do not immerse in saline

Keep cool (4°C) but do not freeze

Enzyme analysis Store in available container Snap freeze in liquid nitrogen and store at –80°C

Electron microscopy Place in container with formalin

or glutaraldehyde

Room temperature

Other as needed by infant’s clinical presentation Consult geneticist or pathologist As instructed

EDTA, ethylenediaminetetraacetic acid.