Crystalluria has become one of the most vital biomarkers in urinalysis in detecting several disease conditions. It has been reported that urinary tract infections (UTI) may be the presenting sign of Urolithiasis in children. Therefore, the objective of this study was to identify and estimate the different types of crystals in the urine samples collected from UTI suspected children who admitted to the Lady Ridgeway Hospital for children, Sri Lanka. A descriptive cross-sectional study was conducted using 400 children belong to age<12 years suspected with UTI. The participants included 242 males and 158 females. The urine samples were collected prior to start antibiotics. Each sample was examined macroscopically and centrifuged at 2000 rpm for 5 minutes. The urine sediment was examined under the light microscope and different crystal types were identified and counted at x40 magnification. Out of 400 samples 82 samples (82/400) were positive for crystalluria. The crystal types present were uric acid, calcium oxalate, triple phosphate, ammonium biuate and ammonium urate. None of the samples showed abnormal crystal types. The distribution of each crystal type was as follow; uric acid 25/82, calcium oxalate 34/82, triple phosphate 12/82, ammonium biuate 7/82 and ammonium urate 4/82. The quantity of crystals per mL of urine was ranged as follow; uric acid 850-130,000, calcium oxalate 350->250,000, triple phosphate 650-6,000, ammonium biurate and ammonium urate were presented in clumps.

Cystinuria contributes in formation of urinary stones. But, it has been reported that cystinuria is diagnosed when someone experiences with cystine stones. Therefore, early diagnosis of this condition is important. Thus, the objective of the study was to determine the optimum pH and temperature for crystallization of urine cystine in-vitro. Cystinuria solutions were prepared with the concentrations of 40, 60, 70, 75, 80, 90, 100 and 120 mg/dL. The pH of each solution was changed with the addition of acetic acid. Then solutions were exposed to temperature +4°C and 37°C, for 15, 30 and 45min. The sediments were observed microscopically for cystine crystals formation. Then acetone was added to cystinuria with the ratio of cystinuria:acetone, 8:1, 4:1, 2:1 and 1.1 and pH was altered with acetic acid and were subjected to +4 °C and 37 °C, for 15, 30 and 45 minutes and sediment was observed for cystine crystals under the microscope. Cystine crystallization had been occurred in the cystinuria of ≥100 mg/dL at pH 5 at 37 ° C and +4 °C, 30min after the addition of acetic acid whereas with the addition of acetone at cystinuria of ≥75mg/dL at pH 5 in both 37°C and at +4°C, 30min after the addition of acetic acid. The number of cystine crystals per High Power Field (HPF) was highest where cystinuria:acetone was 8:1. The optimum conditions for cystine crystallization is at pH 5, 37 °C and +4 °C, 30min after acidifying with acetic acid at the minimum concentration of 100 mg/dL of cystinuria. With the addition of acetone, at the ratio of cystinuria:acetone 8:1 with minimum concentration of cystinuria of 75 mg/dL.