urine preservatives

refrigeration as

• no interference with chemical test

• prevents bacterial growth for 24 hours

thymol as

• preserves glucose and sediments well

boric acid as

• preserves protein and formed elements

• no interference with routine analysis other than pH

formaldehyde as

• excellent sediment preservative

toluene as

• does not interfere with routine test

sodium fluoride as

• prevents glycolysis

• good for drug analysis

phenol as

• no interference with routine tests

commercial preservative tablets as

• convenient when refrigeration is not possible

refrigeration ds

• raises SG by hydrometer

• precipitates amorphous phosphate & urates

thymol ds

• interferes with acid precipitation test for protein

boric acid ds

• may precipitate crystals

formaldehyde ds

• interferes with chemical tests

toluene ds

• floats on urine surface

sodium fluoride ds

• inhibits reagent strip for glucose, blood, leukocytes

phenol ds

• causes an odor change

commercial preservative tablets ds

• may contain one or more preservatives including sodium fluoride

urine collection kits as

• contains collection cup

• culture & sensitivity preservative tube

gray cultured sensitivity tube as

• sample stable at room temp for 48 hrs

• preserves bacteria

yellow plain UA tube as

• use on automated instruments

gray cultured sensitivity tube ds

• decreases pH

yellow plain UA tube ds

• must refrigerate within 2 hours

cherry red/ yellow preservative plus tube as

• stable for 72 hours at room temp

• instrument compatible

cherry red/ yellow preservative plus tube ds

may decrease bilirubin & urobilinogen

saccomano fixative 50% ethanol + 2% carbowax

• preserves cellular elements

• used for cytology studies (50 mL urine)