db/db C57BLKS mouse

小鼠腹腔注射胰岛素后的耐量试验。禁食 4–6 小时；按 1–1.2 U/kg 给予胰岛素；负荷前及负荷后 15、30、60、90、120 分钟测定血糖。不同组别与样本量按具体研究设计确定，本方案不预设实验分组。

FFPE 肾组织切片的 PAS 染色流程，按源方案 FFPE 分支执行脱蜡、复水、氧化、Schiff 显色、苏木素复染、脱水透明和封片。具体切片厚度、视野与定量方法按研究设计确定。

基线与负荷后 15、30、60、90、120 分钟血糖时间序列；可计算血糖下降百分比或曲线下面积。

340 nm吸光度变化对应的葡萄糖浓度。

肾小球基底膜、系膜基质和糖蛋白呈 PAS 阳性（品红/紫红色），细胞核呈蓝色；按研究设计进行肾小球系膜扩张或病变范围判读。

输出为每样品尿白蛋白浓度（mg/l），按标准曲线插值报告；该读数本身不是白蛋白/肌酐比值，换算比值需另测尿肌酐。

Fasting Fasting begins first thing in the morning (around 9am). Fast mice for 4-6 hours before ITT begins. Transfer mice to clean cage and wire top. Keep water bottles during the fasting period. 1. If using High Fat diet (HFD), save food to give back at the end of the ITT. 1. Mark tails with a sharpie for easier identification during ITT. Insulin Solution prep Stock 1: 50ul of 100U/ml Humulin R into 4950ul of cold sterile 1X PBS. Invert solution 3-4 times to mix. Stock 2: 1ml of Stock 1 into 9ml of cold sterile 1X PBS. Invert solution 3-4 times to mix. Keep on ice until use ITT Weigh mouse to obtain body weight for dose calculations. Calculate bolus dose of insulin (**1-1.2 units/kg**). Weight of mouse (g) x 10 = ul insulin stock 2 solution ITT - template spreadsheet.xlsx ITT Prepare syringes using 1cc syringe and 26G needle. Load all syringes with calculated insulin dose and position in front of home cage. ITT Prior to the delivery of the insulin solution, a time “zero” blood glucose level must be measured. Restrain mouse and clean tail with 70% ethanol/gauze. Extract a small amount of blood from the tail vein onto One Touch Ultra blood glucose strips used with the One Touch Ultra 2 blood glucose monitoring system. ITT Administer the correct dose of Insulin solution using an IP (intraperitoneal) injection method. - Restrain the mouse. Then place the mouse is in dorsal recumbency with the head down allowing the viscera to move cranially. - Using the bend of the knee and the ventral abdominal midline as landmarks, the needle is inserted half way between the midline and lateral side of the animal at the natural bend of the knee. Insert the needle at a 30 to 45 degree angle into either the left or right lower abdominal quadrant. - Prior to injection, aspirate to make sure the needle has not penetrated a blood vessel, the intestines or the urinary bladder. When aspirating the syringe, you should see an air bubble in the hub of the needle, and not any form of fluid. - Inject and return mouse to cage. ITT Begin timing from the point of successfully delivering the insulin solution. ITT Test and record the blood glucose level (see step 5) at times 15, 30, 60, 90, and 120 minutes after the initial glucose delivery. Record each value on Insulin Tolerance Test record sheet (template found on step 2). Record condition of animal throughout and after procedure on the Insulin Tolerance Test recored sheet. ITT Return food and environmental enrichments to cages.

Calibrate Cobas for Glucose analysis by running a multi analyte standard and two control serum. Calibrate Cobas for Glucose analysis by running a multi analyte standard and two control serum. Sample Handling as performed by the Cobas Mira Plus. Sample Handling as performed by the Cobas Mira Plus. a) Pipette 3 µL of sample into cuvette. b) Absorbance is measured at 340 nm. c) Add 100 µL of Glucose liquid reagent. d) Mixture is incubated at 37ºC for 10 minutes. e) Absorbance is measured at 340 nm. Change in absorbance is calculated.

Start with FFPE here: Allow PAS “kit” to come to room temperature on the bench. Start with FFPE here: For paraffin sections, deparaffinize in xylene, two changes, 00:03:00 each. Start with FFPE here: Hydrate through graded alcohols, 00:01:00 each: 100%, 100%, 95%, 70%, water Start with FFPE here: Rinse well in distilled water by holding finger over slides, pouring water into sink and adding water. Do this 5 times. Start Frozen samples here: Place in 0.5% Periodic acid for 00:10:00 (to oxidize). Start Frozen samples here: Rinse well in distilled water (follow Step 4). Start Frozen samples here: Pour Schiff’s reagent into Coplin jar containing slides. Allow to sit 15-30 minutes at room temperature (kidney samples ~30 minutes). Start Frozen samples here: Rinse in running warm (~40 °C) distilled or tap water (follow Step 4). The tissue should appear pink after rinsing with warm water. Start Frozen samples here: Place slides in movable gray slide holder. Start Frozen samples here: Counterstain in Hematoxylin (staining line) for 00:01:00. Start Frozen samples here: Rinse well in distilled water, starting with blue container next to hematoxylin (follow Step 4). Start Frozen samples here: Quickly dip slides into “Bluing” agent (0.5% ammonium hydroxide). Start Frozen samples here: Rinse 1 minute in distilled water until pink color is visible (follow Step 4). Start Frozen samples here: Dehydrate through graded alcohols, 10 short dips in each: 95%, 95%, 100%, 100% If the last 100% ethanol rinse is colored by residual stain, additional washing in new 100% ethanol solution should be performed. Start Frozen samples here: Fix in 2 rounds of xylenes, 00:01:00 each (in the hood). Start Frozen samples here: Coverslip slides: - Place coverslip on paper towel - Add 2-3 drops of cytoseal to edge (depending on size) - Dip slide into xylenes, take out and roll the xylene lengthwise on slide - Line up slide and cover slip and slowly place the slide on the coverslip - If needed, use dissecting tool to remove bubbles Start Frozen samples here: Image slides using a Leica brightfield scanner, AxioScan Z1 slide scanner (or equivalent) at 20x (~1 µm spatial resolution) and save as.tiff or.jpg file.

Prepare working reagent. Prepare working reagent. Prepare standards by serially diluting 200 mg/l standard 1:1 to make 100, 50, 25, 12.5, 6.25 standards. Prepare standards by serially diluting 200 mg/l standard 1:1 to make 100, 50, 25, 12.5, 6.25 standards. Add 25 μl of standard and sample to each well. Add 25 μl of standard and sample to each well. Add 125 μl of working reagent. Read in fluorimeter using 590 nm excitation and 616 nm emission. Add 125 μl of working reagent. Read in fluorimeter using 590 nm excitation and 616 nm emission. _**IMPORTANT: **__Make sure not to add any bubbles to the wells when dispensing reagents, this will interfere with reading in the platereader._ Use a polynomial 2nd order curve fit to construct a standard curve. Interpolate the values of the unknowns using the sta Use a polynomial 2nd order curve fit to construct a standard curve. Interpolate the values of the unknowns using the standard curve.