ALAT Formulas and Calculations

Question 1

An animal room is maintained at 68°F. What is this temperature in Celsius?

Accepted Answer

20°C

Answer

The formula is °C = (°F − 32) × 5/9. So (68 − 32) × 5/9 = 36 × 5/9 = 20°C. The recommended temperature range for most laboratory rodents is 18–26°C (64–79°F).

Question 2

You need to make 100 mL of a 1:10 dilution of a disinfectant in water. How many mL of disinfectant do you use?

Accepted Answer

10 mL

Answer

A 1:10 dilution means 1 part concentrate per 10 parts total solution. For 100 mL total: 100 ÷ 10 = 10 mL of disinfectant, then add 90 mL of water to reach 100 mL.

Question 3

A mouse weighs 25 grams and requires a drug at 10 mg/kg. What dose in mg should the mouse receive?

Accepted Answer

0.25 mg

Answer

First convert grams to kilograms: 25 g = 0.025 kg. Then: 0.025 kg × 10 mg/kg = 0.25 mg. Accurate weight-based dosing is critical for both animal welfare and experimental validity.

Question 4

You need 1 liter of a 2% disinfectant solution. Your stock is 20% concentration. How many mL of stock do you need?

Accepted Answer

100 mL

Answer

Using the dilution formula C1V1 = C2V2: (20%) × V1 = (2%) × 1000 mL, so V1 = 2000 / 20 = 100 mL of stock. Add water to bring the total volume to 1000 mL.

Question 5

A room thermometer reads 30°C. The acceptable range for the species housed is 64–79°F. Is this within range?

Accepted Answer

No — 30°C equals 86°F, which is too warm

Answer

Converting: °F = (30 × 9/5) + 32 = 54 + 32 = 86°F. Since 86°F exceeds the upper limit of 79°F, the temperature is out of range and must be reported immediately as an abnormal environmental parameter.

ALAT - Assistant Laboratory Animal Technician Practice Test

ALAT - Assistant Laboratory Animal Technician Practice Test

ALAT Formulas and Calculations