Dry measure cups are great for catching urine samples. Since Lady is diabetic and prone to UTI's, I keep the strips at home so I can test her myself.
Amazon.com: Multistix 10 S G Reagent Strips for...
My vet will usually just prescribe a round of Baytril based upon my test, but sometimes tests it herself. We always do a sterile culture if it doesn't clear up right away. Most UTI's are caused by E-coli which can be very resistant to antibiotics. Sometimes you are dealing with several different strains at the same time. A culture will tell your vet exactly what antibiotics are needed.