LAB Techniques Measurement, Tools, Skills aka: what you’ll be doing in the lab ALL year long
Jan 04, 2016
LAB TechniquesMeasurement, Tools, Skills
aka: what you’ll be doing in the lab ALL year long
Measurement
• In science, we use the metric system. – Don’t Forget! “Inches” is a swear word. Don’t
use it in this classroom.
• We will use measurements to find the mass, volume, and length of various objects.
Length Measurement• To measure length, we will typically use a
ruler.
• We measure in centimeters.
• It’s actually a good idea to not measure at “0”
Volume Measurement
• To measure the volume of something solid:– L x W x H– measure in “cm”– volume units are cm3
Volume Measurement
• A commonly used instrument to measure liquid volume is the graduated cylinder.
• We measure the liquid volume in milliliters (ml).
Mass Measurement
• The triple beam balance is commonly used to measure mass in the biology lab.
• Masses on a triple-beam balance can be measured in grams.
Lab Tools We Will Be Using
• Some tools you’ll need to familiarize yourself with:– Microscopes– Paper Chromatography– Gel Electrophoresis
Microscopes
• We will be observing several objects that are difficult or impossible to see with the naked eye.
• Microscopes provide magnification into the world of smaller organisms.
• Two microscopes we will use in the lab:– Compound light microscope– Dissecting microscope
Chromatography• Paper chromatography is a
procedure used to separate substances in a mixture.
• Typically, the substances that are moved are pigments.
• This process occurs because of capillary action.
Gel Electrophoresis
• Gel electrophoresis is a procedure used to separate charged molecules of different sizes by passing them through a gel in an electrical field.
• We use this process to compare DNA strains.
• The DNA is cut by enzymes, then moved through the gel according to size.
Laboratory Skills
• When you’re in the lab, besides using tools, you’ll also need to practice appropriate skills. This year, we will focus on using and understanding:– Indicators– Dichotomous Keys– Dissection Techniques
Indicators
• Indicators are substances which are used to provide information about the classification of a particular substance.
• Some commonly used indicators in the living environment/biology lab include:– Litmus (pH) paper– Lugol's (iodine) solution – Benedict's solution.
Dichotomous Keys
• Making sense of observations is important in science. Classification provides a means of describing objects or organisms by their common characteristics.
very BASIC example
Dichotomous Keys
• A dichotomous key is used to provide a method of sorting categories of organisms and specifically identifying particular organisms.
Dissection Techniques
• The dissection of representative plant and animal specimens is a required skill for the living environment/biology course.
• Dissection provides information about the internal and external characteristics of a specimen in a direct manner which other techniques can not directly provide.
Dissection Techniques
• Specimens we’ll be looking at include:– Flowers– Frogs– Fetal Pigs