Phosphorous, Serum

Phosphorous, Serum

Alternate Test Name

PO4

Epic Mnemonic
Sunquest Mnemonic

LAB113
PHOS

Category

Chemistry

Methodology

Molybdate UV

Test Performance Schedule

Sunday - Saturday

Result Availability

Within 24 hours – STAT upon request

Container

Gold top (SST), Red top (serum), or Green top (lithium heparin) tube

Alt: EDTA

Volume

Pref. Vol.: 1.0 mL
Min. Vol.: 0.5 mL

Collection Instructions

• Routine venipuncture

• Immediately after collection, gently invert tube 5-10 times

• Clot 30 minutes

• Promptly centrifuge

• If no gel barrier is present immediately transfer serum or plasma to a plastic tube and refrigerate

• Properly centrifuged gel barrier tube does not require transfer of serum or plasma to separate tube

Transportation Instructions

Refrigerated

Stability

• Room Temperature: 1 day

• Refrigerated: 4 days

CPT Codes

84100

Effective/Revised

03/28/2017

88% of the phosphorus contained in the body is localized in bone in the form of calcium phosphate. The remainder is involved in intermediary carbohydrate metabolism and in physiologically important substances such as phospholipids, nucleic acids and ATP. Phosphorus occurs in blood in the form of inorganic phosphate and in organically bound phosphoric acid. The small amount of extracellular organic phosphorus is found almost exclusively in the form of phospholipids.

The ratio of phosphate to calcium in the blood is approximately 6:10. An increase in the level of phosphorus causes a decrease in the calcium level. The mechanism is influenced by interactions between parathormone and vitamin D. Hypoparathyroidism, vitamin D intoxication and renal failure with decreased glomerular phosphate filtration give rise to hyperphosphatemia. Hypophosphatemia occurs in rickets, hyperparathyroidism and Fanconi's syndrome.