DESCRIPTION

Lactoferrin (LTF), known as an iron-binding glycoprotein, is the most abundant element in milk. Prior research has illustrated that LTFbears multi-pharmacological properties, including protection against infection, regulation inflammatory response, antioxidant and antifibrotic process. Moreover, clinical trials have identified the safety of oral administration of bovine LTF and demonstrated the efficacy of LTF on anti-infection, treatment of inflammation, cancer, metabolic disorders.

PRINCIPLE OF THE ASSAY

An anti-tag antibody is pre-coated onto the bottom of wells. After adding antigen or samples, Tagged-Capture antibody and HRP-conjugated detection antibody, a sandwich complex is formed in the solution. TMB acts as a HRP substrate, and the solution color will change from colorless to blue. A stop solution containing sulfuric acid turns the solution yellow. The color intensity is proportional to the quantity of bound protein, which is measurable at 450 nm with the correction wavelength set at 630 nm.

PRECISION

Intra-assay Precision (Precision within an assay) Three samples of known concentration were tested 8 times on one plate to assess intra-assay precision. Inter-assay Precision (Precision between assays) Three samples of known concentration were tested in 16 separate assays to assess inter-assay precision.

Intra-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	8	537.2	22.8	4.2
2	8	140.3	14.7	10.5
3	8	71.0	2.05	2.9

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	16	570.2	40.0	7.0
2	16	141.1	13.2	9.4
3	16	70.9	2.4	3.3

RECOVERY

The recovery of human Lactoferrin/LTF spiked to three different levels throughout the range of the assay in various matrices was evaluated.

Sample Type		Average% of Expected	Range (%)
Human plasma	1:800	99	95-102
	1:1,600	84	76-93
Urine	1:32	96	90-102
Saliva	1:51,200	92	85-98
	1:102,400	98	89-109

LINEARITY

To assess the linearity of the assay, samples were diluted with the appropriate Sample Diluent to produce samples with values within the dynamic range of the assay. (The human plasma was initially diluted 1:100. The urine was initially diluted 1:8. The saliva samples were initially diluted 1:6,400.)

		Human plasma	Urine	Saliva
1:2	Average% of Expected	100	100	100
	Range (%)	-	-	-
1:4	Average% of Expected	95	104	104
	Range (%)	90-100	94-114	99-108
1:8	Average% of Expected	105	108	101
	Range (%)	99-111	101-115	100-102
1:16	Average% of Expected	104	103	106
	Range (%)	97-111	96-110	105-107

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant human Human Lactoferrin/LTF One-Step ELISA Kit produced at Sunlong Medical™.