Urinalysis - The Carter Center

It requires large volumes ( 0.5 to 5 ml ) and requires either
disposable tubes or glass tubes which must be cleaned for re-use.
The results of the precipitation tests are read in terms of the amount of
precipitate or turbidity that is formed in a test tube ( in case of Heat and
acetic acid, and Sulphosalicylic acid tests ) or in terms of the size of
ring of contact between reagents in case of Robert`s and Heller`s
tests. The amount of turbidity or precipitation is roughly proportional to
the amount of protein present in the urine specimen, and the results are
generally graded as negative, trace, 1+, 2+, 3+, or 4+.
Since the result in precipitation tests is determined by the presence of
either turbidity or a precipitate, it is important that the urine be free from
particles or clear before the test is performed. To clear the urine, it
should be filtered or centriguged. The clear filtrate is tested for the
presence of protein.
The non-ring precipitation is read and interpreted as follows :
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Negative - No turbidity, or no increase in turbidity ( approximately 5
mg/dL or less)
Trace - Perceptible turbidity ( approximately 20 mg /dL).
1+ - Distinct turbidity, but no discrete granulation (approximately
50 mg/dL ).
2+ - Turbidity with granulation, but no flocculation (approximately
200 mg/dL).
3+ - Turbidity with granulation and flocculation ( approximately
500 mg/dL).
4+ - Clumps of precipitated protein, or solid precipitate
(approximately 1000mg/dL or more )
The Ring Test is read as follows:-
Negative - No cloudiness appears at the zone of contact