Difference Between Amorphous Urate and Phosphate

The key difference between amorphous urate and phosphate is that amorphous urate appears as dark or yellow-red granules whereas amorphous phosphate appears as colourless or white colour.

Amorphous urate and amorphous phosphate are important terms that are discussed regarding the composition of urine. Amorphous urate and phosphate are present in urine in different compositions depending on the pH of urine. For example, acidic urine has more amorphous urate while alkaline urine has more amorphous phosphate.

CONTENTS

1. Overview and Key Difference
2. What is Amorphous Urate 
3. What is Amorphous Phosphate
4. Side by Side Comparison – Amorphous Urate vs Phosphate in Tabular Form
5. Summary

What is Amorphous Urate?

Amorphous urate is a component in acidic urine. It appears in a dark colour or as yellow red-coloured granules. Amorphous urate can be found in urine having a low pH value because the composition of this compound in urine depends mainly on the urine pH.

Presence of the crystals of amorphous urate in acidic urine is considered as a normal state if this substance forms from solutes that we can typically find in the urine. This substance usually forms when urine is cooled after the collection of the sample. Other than that, crystalline uric acid is also considered as a normal component in the urine. However, high percentages of amorphous urate in urine are not healthy; it requires treatment such as alkalinization using citrate or bicarbonate and dilution by intake of a large amount of water.

Figure 01: A Urine Crystal

Presence of a high amount of amorphous urate in the urine causes the formation of amorphous urate crystals in urine. For example, sodium, potassium, magnesium and calcium urate salt compounds precipitate from acidic urine in its amorphous form. Although these crystals of amorphous urate resemble the crystals of amorphous phosphate, there is a difference between them; amorphous urate crystals dissolve in alkaline solutions where amorphous phosphate crystals do not.

What is Amorphous Phosphate?

Amorphous phosphate is a component in alkaline urine. It appears as a colourless substance or as a white colour substance. Presence of a low amount of amorphous phosphate in urine is considered a normal condition. However, if the percentages are high, it can indicate that the patient has kidney disease. It is possible to dissolve the amorphous phosphate crystals that form in urine by adjusting the pH of the urine sample; by adding a drop of 2% acetic acid. Amorphous urate crystals, on the other hand, can be dissolved by adding an alkali solution such as 2% ammonia.

Figure 02: Different Crystals in a Urine Sample

Amorphous phosphate in urine refers to the granular precipitate containing calcium and phosphate in an alkaline urine solution. High amounts of amorphous phosphate in urine can be treated by using calcium carbonate tablets under the supervision of a consultant.

What is the Difference Between Amorphous Urate and Phosphate?

Amorphous urate and amorphous phosphate are important terms that are discussed regarding the composition of urine. The key difference between amorphous urate and phosphate is that amorphous urate appears in dark or yellow-red granules whereas amorphous phosphate appears as colourless or white colour.

Below infographic tabulates the differences between amorphous urate and phosphate in more detail.

Summary – Amorphous Urate vs Phosphate

Amorphous urate and amorphous phosphate are important terms that are discussed regarding the composition of urine. The key difference between amorphous urate and phosphate is that amorphous urate appears in dark or yellow-red granules whereas amorphous phosphate appears as colourless or white colour.

Reference:

1. “Amorphous Urates” – LabCE.com, Laboratory Continuing Education, Available here.

Image Courtesy:

1. “Urine crystal” By Bobjgalindo – Own work (CC BY-SA 4.0) via Commons Wikimedia
2. “Struvite crystals dog with scale 1” By Joel Mills – Own work (CC BY-SA 3.0) via Commons Wikimedia

ncG1vNJzZmivp6x7pbXFn5yrnZ6YsqOx07CcnqZemLyue8OinZ%2Bdopq7pLGMm5ytr5Wau26tzKipqaCfqsBuwdGaq55lkaOxbrzHqKqpoJGpsnA%3D