ACTIVITY 4-6: CULTURE MEDIA PREPARATION

Materials use in ACTIVITY 4

2 petri dish

1 culture tube

2 coconut midribs (tukog)

2 scratch papers

CULTURE MEDIA PREPARATION

Activity 4 titled

NUTRIENT AGAR

NUTRIENT BROTH

1. Weigh the corresponding amount of nutrient agar for a 500ml distilled water.
    2. Stir and mix over a boiling water until is it evenly distributed

NUTRIENT AGAR

Autoclave at 121 degree celcius for 15 minutes, 15 psi.

  After autoclaving and cooling it down, dispense around 15-20 ml unto your petri dish.

Let it cool down and place it inside the refrigerator for storage.

NUTRIENT BROTH

Dispense around 5-10 ml unto your culture tube.

Autoclave at 121 degree celcius for 15 minutes, 15 psi.

Let it cool down and place it inside the refrigerator for storage.

Preparing the Bacterial Cultures

ACTIVITY 5 titled

1 alcohol lamp

1 wire loop

Materials used in activity 5

Nutrient broth

Step 1

Remove the cover of your cotton swab and wet it using your … sample.

area

Step 2

Choose an … of your choice (table tap, floor, door knob, stair railing, money, skin, shoes). Swab the area using your cotton swab.

Petri dish

test tube

Swab your cotton swab on a small area in your … (I will illustrate it in class). Put back your cotton swab in the …. Cover it loosely.

alcohol lamp

20 times

Step 4

Heat your wire loop until red hot using the …. Cool it by waiving … in the air.

rim

Step 5

Heat the … of your petri dish using your alcohol lamp.

multiple interrupted streak method

Step 6

Do a …using your wire loop (I will demonstrate it in class) from the swabbed area in your petri dish using your wire loop.

37 Degrees celcius in an upside-down position

18-72 hours

Final step

Put your petri dish in the incubator at …. Incubate it for ….

Pellicle formation

growth near the surface and on the sides

It can be seen on the surface of the broth, observed as thin cohesive layer (waxy pellicle).

Turbidity

change in color, becomes hazy

It shows medium turbid or little cloudiness, an indication of bacterial growth.

Sediments

growth at the bottom of the tube

observed as gelatinous sediment (found in the bottom of the broth), and has heavy turbidity showing microbial growth.

Pellicle formation

Turbidity

Sediments

Nutrient broth can be described

Circular

Rhizoid

Irregular

Filamentous

Spindle

Nutrient agar shape

Entire

Undulate

Lobate

Curled

Rhizoid

Filamentous

Nutrient agar margin

Flat

Raised

Convex

Pulvinv

Nutrient agar elevation

Punctiform

Small

Moderate

Large

Nutrient Agar Size

Smooth or rough

Nutrient Agar Texture

glistening (shiny) dull

Nutrient Agar appearance

cream, tan, white

Nutrient agar non pigmented

purple, red, yellow

Nutrient agar pigmented

opaque, translucent, transparent

Nutrient Agar optica property