DESCRIPTION

Prolactin (PRL), a polypeptide hormone that is primarily (but not only) secreted by the lactotrophic cells of the pituitary gland, is a critical element of the immune-neuroendocrine network. Prolactin belongs to the prolactin/growth hormone/placental lactogen family. Besides proteolytic cleavage, the majority of prolactin variants can be the result of other posttranslational processing of the mature molecule in the anterior pituitary gland or the plasma. These include dimerization and polymerization, phosphorylation, glycosylation, sulfation, and deamidation. Prolactin has been shown to stimulate intestinal calcium absorption, increase bone turnover, and reduce renal calcium excretion.

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	608.3	22.6	3.7
2	8	141.0	3.0	2.1
3	8	75.6	1.3	1.7

Inter-assay Precision

Sample	n	Mean (pg/mL)	SD	CV%
1	16	593.6	26.4	4.4
2	16	139.0	3.4	2.4
3	16	76.2	1.8	2.4

RECOVERY

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

Sample Type		Average% of Expected	Range (%)
Human plasma	1:32	114	112-116
	1:64	112	102-119
Human milk	1:32	123	117-126

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 human milk was initially diluted 1:4.)

		Human plasma	Human milk
1:2	Average% of Expected	100	100
	Range (%)	-	-
1:4	Average% of Expected	110	98
	Range (%)	101-119	98-99
1:8	Average% of Expected	121	99
	Range (%)	116-127	98-99
1:16	Average% of Expected	120	108
	Range (%)	120-121	98-118

CALIBRATION

This immunoassay is calibrated against a highly purified recombinant human Prolactin produced at Sunlong Medical™.